CH, Ch, cH, or ch may refer to:

Arts and entertainment

Television channel A television channel is a terrestrial frequency or virtual number over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the terrestrial or cable band of 54 to 60 MHz, with ...

(sometimes abbreviated as "ch." for television and cable stations) * ''

Chaos;Head ''Chaos;Head'' (stylized as ''ChäoS;HEAd'') is a 2008 science fiction visual novel video game developed by 5pb. and Nitroplus. It is the first game in the ''Science Adventure'' series. Following the original Windows release, the enhanced ver ...

'', a video game * ''

Clone Hero ''Clone Hero'' is a freeware music rhythm video game created by Ryan Foster, first released in alpha on March 1, 2017, receiving a full release on November 29, 2022. The game is a clone of the ''Guitar Hero'' franchise with nearly identical ...

'', a clone game version of popular rhythm game series ''

Guitar Hero ''Guitar Hero'' is a series of music rhythm game video games first released in November 2005, in which players use a guitar-shaped game controller to simulate playing primarily lead, bass guitar, and rhythm guitar across numerous songs. Player ...

''. *

CollegeHumor CollegeHumor is an Internet comedy company based in Los Angeles. Aside from producing content for release on YouTube, it was also a former humor website owned by InterActiveCorp ( IAC) until January 2020, when IAC withdrew funding and the websi ...

, a comedy website * E!, a defunct Canadian television system that went by the name CH from 2001 to 2007

Businesses

Bemidji Airlines Bemidji Airlines (Bemidji Aviation Services Inc) is an American airline based in Bemidji, Minnesota, USA. It operates domestic cargo flights, as well as extensive charter and air taxi services. Its main base is Bemidji Regional Airport, with hub ...

(IATA code CH) *

Carolina Herrera Carolina Herrera (born María Carolina Josefina Pacanins y Niño; 8 January 1939) is a Venezuelan-American fashion designer known for her personal style, and for dressing various First Ladies, including Jacqueline Onassis, Laura Bush, Michel ...

, a fashion designer based in New York *

Columbia Helicopters Columbia Helicopters, Incorporated (CHI) is an aircraft manufacturing and operator company based in Aurora, Oregon, United States. It is known for operating tandem rotor helicopters; in present times, exclusively the Boeing Vertol 107 and Boeing ...

, an aircraft manufacturing and operator company based in Aurora, Oregon, United States

In language

Ch (digraph) Ch is a digraph in the Latin script. It is treated as a letter of its own in Chamorro, Old Spanish, Czech, Slovak, Igbo, Uzbek, Quechua, Guarani, Welsh, Cornish, Breton, Ukrainian Łatynka and Belarusian Łacinka alphabets. Formerly ch ...

, considered a single letter in several Latin-alphabet languages *

Chamorro language Chamorro (; ch, Finuʼ Chamorro, links=no (CNMI), (Guam)) is an Austronesian language spoken by about 58,000 people (about 25,800 people on Guam and about 32,200 in the rest of the Mariana Islands and elsewhere). It is the native and spoken ...

: ISO 639 alpha-2 language code (ch)

Science and technology

Chemistry

* The

methylidyne radical Methylidyne, or (unsubstituted) carbyne, is an organic compound whose molecule consists of a single hydrogen atom bonded to a carbon atom. It is the parent compound of the carbynes, which can be seen as obtained from it by substitution of other f ...

(a carbyne); CH^• (or •CH), CH^3• (or ⫶CH) * The

methylidyne group In organic chemistry, a methylidyne group or just methylidyne is a neutral part of a molecule (a substituent or functional group) with formula , consisting of a carbon atom bonded to a hydrogen atom by one single bond and to the rest of the molecu ...

≡CH * The

methine group In organic chemistry, a methine group or methine bridge is a trivalent functional group , derived formally from methane. It consists of a carbon atom bound by two single bonds and one double bond, where one of the single bonds is to a hydrogen. T ...

(methanylylidene, methylylidene) =CH−

Mathematics and computing

Chomsky hierarchy In formal language theory, computer science and linguistics, the Chomsky hierarchy (also referred to as the Chomsky–Schützenberger hierarchy) is a containment hierarchy of classes of formal grammars. This hierarchy of grammars was described by ...

, in computer science, a containment hierarchy of classes of formal grammars *

Continuum hypothesis In mathematics, the continuum hypothesis (abbreviated CH) is a hypothesis about the possible sizes of infinite sets. It states that or equivalently, that In Zermelo–Fraenkel set theory with the axiom of choice (ZFC), this is equivalent to ...

, in set theory *

Hyperbolic cosine In mathematics, hyperbolic functions are analogues of the ordinary trigonometric functions, but defined using the hyperbola rather than the circle. Just as the points form a circle with a unit radius, the points form the right half of the u ...

, in mathematics, a hyperbolic function, ch(x) = cosh(x) *

Curry–Howard correspondence In programming language theory and proof theory, the Curry–Howard correspondence (also known as the Curry–Howard isomorphism or equivalence, or the proofs-as-programs and propositions- or formulae-as-types interpretation) is the direct relati ...

, the relationship between computer programs and mathematical proofs *

CH register x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was intr ...

, the high byte of an X86 16-bit CX register *

Ch (computer programming) Ch is a proprietary cross-platform C and C++ interpreter and scripting language environment, originally designed by Harry H. Cheng as a scripting language for beginners to learn mathematics, computing, numerical analysis (numeric methods), and ...

, a cross-platform C/C++ interpreter *

Contraction hierarchies In computer science, the method of contraction hierarchies is a speed-up technique for finding the shortest-path in a graph. The most intuitive applications are car-navigation systems: a user wants to drive from A to B using the quickest possible ...

, in computer science, a speed-up technique for finding shortest paths in a graph

Medicine

Cluster headache Cluster headache (CH) is a neurological disorder characterized by recurrent severe headaches on one side of the head, typically around the eye(s). There is often accompanying eye watering, nasal congestion, or swelling around the eye on the a ...

Cholesterol Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ...

Congenital hypothyroidism Congenital hypothyroidism (CH) is thyroid hormone deficiency present at birth. If untreated for several months after birth, severe congenital hypothyroidism can lead to growth failure and permanent intellectual disability. Infants born with cong ...

, a condition of thyroid hormone deficiency present at birth *

Cerebellar hypoplasia Cerebellar hypoplasia is characterized by reduced cerebellar volume, even though cerebellar shape is (near) normal. It consists of a heterogeneous group of disorders of cerebellar maldevelopment presenting as early-onset non–progressive conge ...

, characterized by reduced cerebellar volume :*

Cerebellar hypoplasia (non-human) Cerebellar hypoplasia (CH) is a neurological condition in which the cerebellum is smaller than usual or not completely developed. It has been reported in many animal species. Function and development of the cerebellum The cerebellum is the b ...

French catheter scale The French scale, French gauge or Charrière system is commonly used to measure the size of a catheter. It is most often abbreviated as Fr, but can often be seen abbreviated as Fg, FR or F. It may also be abbreviated as CH or Ch (for Charrière, i ...

, a scale for medical catheters, also abbreviated as ''Fr''

Military technology

Cargo helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

(U.S. military helicopter alpha-numeric prefix) *

Chain Home Chain Home, or CH for short, was the codename for the ring of coastal Early Warning radar stations built by the Royal Air Force (RAF) before and during the Second World War to detect and track aircraft. Initially known as RDF, and given the off ...

, a World War II radar array *

Heavy cruiser The heavy cruiser was a type of cruiser, a naval warship designed for long range and high speed, armed generally with naval guns of roughly 203 mm (8 inches) in caliber, whose design parameters were dictated by the Washington Naval Tr ...

(U.S. Navy ship code CH, standing for "Cruiser, Heavy")

In other sciences

Clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

of high plasticity (USCS soil type CH) * Cassini-Huygens

Places

Confoederatio Helvetica ; rm, citad federala, links=no). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzon ...

, the formal name for Switzerland, Latin in origin **

ISO country code ISO 3166 is a standard published by the International Organization for Standardization (ISO) that defines codes for the names of countries, dependent territories, special areas of geographical interest, and their principal subdivisions (e.g., ...

for Switzerland **

.ch .ch is the country code top-level domain (ccTLD) for Switzerland in the Domain Name System of the Internet. Made available in 1987, only two years after .com, it is administered by SWITCH Information Technology Services. The domain ''ch'', as ...

, the Internet country code top-level domain for Switzerland *

CH postcode area The CH postcode area, also known as the Chester postcode area, is a group of 37 postcode districts in north-west England and north-east Wales, which are subdivisions of thirteen post towns. These districts cover west Cheshire (including Chester, ...

; the Chester postcode area in the UK *

Chihuahua (state) Chihuahua (), officially the Free and Sovereign State of Chihuahua ( es, Estado Libre y Soberano de Chihuahua), is one of the 31 states which, along with Mexico City, comprise the 32 federal entities of Mexico. It is located in northwestern Mex ...

, the State of Chihuahua, Mexico *

Conservation Halton Conservation Halton, also known as the Halton Region Conservation Authority, is a conservation authority established under the Conservation Authorities Act of Ontario. It forms a partnership with the Province of Ontario, the Ministry of Natural ...

, in Ontario, Canada *

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

(FIPS and NATO country code CH)

Other uses

Chain (length) The chain is a unit of length equal to 66 feet (22 yards). It is subdivided into 100 links (PDF) or 4 rods. There are 10 chains in a furlong, and 80 chains in one statute mile. In metric terms, it is 20.1168 m long. By extension, chainage (ru ...

, a unit of linear measure in the Imperial system *

Championship (dog) Championships are awarded to dogs who have passed through a process of selection at dog shows. Traditionally, a championship was received at a conformation show, but championships are now offered for dogs who have attained a high degree of perfect ...

, a dog qualifying for a championship at a conformation show, prefixed "Ch." *

Christ's Hospital Christ's Hospital is a public school (English independent boarding school for pupils aged 11–18) with a royal charter located to the south of Horsham in West Sussex. The school was founded in 1552 and received its first royal charter in 1553 ...

, Horsham, West Sussex *

Companion of Honour The Order of the Companions of Honour is an order of the Commonwealth realms. It was founded on 4 June 1917 by King George V as a reward for outstanding achievements. Founded on the same date as the Order of the British Empire, it is sometimes ...

, a British and Commonwealth honour *

Chaudhary Chaudhary (or Choudhary ; also: Chaudhuri, Choudhuary, Chowdhury) is a hereditary title mainly in South Asia, mainly used by Jats, Gurjar and Bhumihars. Chowdhury (Hindi: चौधरी/चौधुरी/चौधारी; Urdu: چودھر� ...

, an honorific used in the Indian and Pakistani Punjab regions *

Metres above the Sea (Switzerland) Metres above the Sea (German: ''Meter über Meer (m ü. M.)'') is the vertical datum used in Switzerland. Both the system and the term are also used in the Principality of Liechtenstein. Use In Switzerland, levelled heights from the ...

, an elevation reference system * The logo for the

Montreal Canadiens The Montreal CanadiensEven in English, the French spelling is always used instead of ''Canadians''. The French spelling of ''Montréal'' is also sometimes used in the English media. (french: link=no, Les Canadiens de Montréal), officially ...

ice hockey team {{disambiguation