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, wit ...

(sometimes abbreviated as "ch." for television and cable stations) * '' Chaos;Head'', a video game * '' Clone Hero'', a clone game version of popular rhythm game series '' Guitar Hero''. * CollegeHumor, a comedy website * E!, a defunct Canadian television system that went by the name CH from 2001 to 2007

Businesses

* Bemidji Airlines (IATA code CH) * Carolina Herrera, 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 CH-46 Sea Knight, Boeing Vert ...

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

In language

* Ch (digraph), considered a single letter in several Latin-alphabet languages * Chamorro language: ISO 639 alpha-2 language code (ch)

Science and technology

Chemistry

* The methylidyne radical (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 (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 ...

, 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 ...

, in set theory * Hyperbolic cosine, in mathematics, a hyperbolic function, ch(x) = cosh(x) * Curry–Howard correspondence, the relationship between computer programs and mathematical proofs * CH register, the high byte of an X86 16-bit CX register * Ch (computer programming), 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 possibl ...

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

Medicine

* Cluster headache * Cholesterol * Congenital hypothyroidism, a condition of thyroid hormone deficiency present at birth * Cerebellar hypoplasia, characterized by reduced cerebellar volume :* Cerebellar hypoplasia (non-human) *

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, ...

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

Military technology

* Cargo helicopter (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 th ...

, a World War II radar array * Heavy cruiser (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 part ...

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

Places

* Confoederatio Helvetica, the formal name for Switzerland, Latin in origin ** ISO country code 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 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 Political divisions of Mexico, 32 federal entities of Mexico. It ...

, the State of Chihuahua, Mexico * Conservation Halton, in Ontario, Canada * China (FIPS and NATO country code CH)

Other uses

* Chain (length), 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 perfec ...

, a dog qualifying for a championship at a conformation show, prefixed "Ch." * Christ's Hospital, 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 sometime ...

, a British and Commonwealth honour * Chaudhary, an honorific used in the Indian and Pakistani Punjab regions * Metres above the Sea (Switzerland), 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