Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to: * Atomic nucleus, the very dense central region of an atom *

Cell nucleus The cell nucleus (pl. nuclei; from Latin or , meaning ''kernel'' or ''seed'') is a membrane-bound organelle found in eukaryotic cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, h ...

, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucleus may also refer to:

Science, technology, and mathematics

Astronomy

* Active galactic nucleus in astronomy * Comet nucleus, the solid, central part of a comet

Biology

, a central organelle of a eukaryotic cell, containing most of the cell's DNA * Nucleus (neuroanatomy), a cluster of cell bodies of neurons in the central nervous system *Nucleus that forms in the eye in nuclear sclerosis (early cataracts) *''Nucleus'', a scientific journal concerned with the cell nucleus; published by Taylor & Francis * Nucleus, a small colony of honeybees, induced to raise a new queen by the beekeeper

Computer systems

Nucleus (operating system) The kernel is a computer program at the core of a computer's operating system and generally has complete control over everything in the system. It is the portion of the operating system code that is always resident in memory and facilitates in ...

, sometimes a synonym for kernel *

Nucleus CMS Nucleus CMS is an open-source blog management software package written in PHP, with a MySQL backend. It is used to manage frequently-updated Web content. With a little tweaking (mainly to skins), it might be considered a lightweight content manage ...

, a weblog system * Nucleus RTOS, a real-time operating system (RTOS) * Nucleus, part of an operating system loaded by an

Initial Program Load In computing, booting is the process of starting a computer as initiated via hardware such as a button or by a software command. After it is switched on, a computer's central processing unit (CPU) has no software in its main memory, so s ...

or boot loader

Mathematics

* Nucleus (algebra), the elements of a ring that associate with all others *

Nucleus (order theory) In mathematics, and especially in order theory, a nucleus is a function F on a meet-semilattice \mathfrak such that (for every p in \mathfrak): # p \le F(p) # F(F(p)) = F(p) # F(p \wedge q) = F(p) \wedge F(q) Every nucleus is evidently a monoton ...

, a mathematical term

Other sciences

Nucleus (syllable) A syllable is a unit of organization for a sequence of speech sounds typically made up of a syllable nucleus (most often a vowel) with optional initial and final margins (typically, consonants). Syllables are often considered the phonological "bu ...

, in linguistics, the central part of a syllable * Atomic nucleus, the very dense central region of an atom * Condensation nucleus, the seed of a raindrop ** Ice nucleus, the seed of a snowflake

Arts and media

* Nucleus (band), a jazz-rock band from Britain * ''Nucleus'' (video game), a 2007 downloadable game on the PlayStation Store * ''Nucleus'' (Anekdoten album), 1995 * ''Nucleus'' (Sonny Rollins album), 1975 * Nucleus, predecessor to Canadian rock band A Foot in Coldwater * ''Nucleus'', a scientific journal concerned with the cell nucleus; published by Taylor & Francis

Other uses

* Nucleus (advocacy group), a UK-European political advocacy campaign organisation * Nucleus Limited, an Australian medical research company, taken over by Pacific Dunlop in 1988 * NuCLEus, a proposed 54-story mixed use building in Cleveland, Ohio, US * Nucleus, the Nuclear and Caithness Archives, a British national archive