nucleus, cell nucleus, karyon
(noun) a part of the cell containing DNA and RNA and responsible for growth and reproduction
nucleus
(noun) any histologically identifiable mass of neural cell bodies in the brain or spinal cord
core, nucleus, core group
(noun) a small group of indispensable persons or things; “five periodicals make up the core of their publishing program”
nucleus
(noun) the positively charged dense center of an atom
nucleus
(noun) (astronomy) the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail
Source: WordNet® 3.1
nucleus (plural nuclei or nucleuses)
The core, central part of something, around which other elements are assembled.
An initial part or version that will receive additions.
(chemistry, physics) The massive, positively charged central part of an atom, made up of protons and neutrons.
(cytology) A large membrane-enclosed organelle found in eukaryotic cells which contains genetic material.
(neuroanatomy) A ganglion, cluster of many neuronal bodies where synapsing occurs.
(phonetics, phonology) The central part of a syllable, most commonly a vowel.
Coordinate terms: onset, coda
• nucules, unclues
Source: Wiktionary
Nu"cle*us, n.; pl. E. Nucleuses, L. Nuclei. Etym: [L., a kernel, dim. fr. nux, nucis, nut. Cf. Newel post.]
1. A kernel; hence, a central mass or point about which matter is gathered, or to which accretion is made; the central or material portion; -- used both literally and figuratively. It must contain within itself a nucleus of truth. I. Taylor.
2. (Astron.)
Definition: The body or the head of a comet.
3. (Bot.) (a) An incipient ovule of soft cellular tissue. (b) A whole seed, as contained within the seed coats.
4. (Biol.)
Definition: A body, usually spheroidal, in a cell or a protozoan, distinguished from the surrounding protoplasm by a difference in refrangibility and in behavior towards chemical reagents. It is more or less protoplasmic, and consists of a clear fluid (achromatin) through which extends a network of fibers (chromatin) in which may be suspended a second rounded body, the nucleolus (see Nucleoplasm). See Cell division, under Division.
Note: The nucleus is sometimes termed the endoplast or endoblast, and in the protozoa is supposed to be concerned in the female part of the reproductive process. See Karyokinesis.
5. (Zoöl.) (a) The tip, or earliest part, of a univalve or bivalve shell. (b) The central part around which additional growths are added, as of an operculum. (c) A visceral mass, containing the stomach and other organs, in Tunicata and some mollusks.
Source: Webster’s Unabridged Dictionary 1913 Edition
27 December 2024
(adjective) restricted to a particular condition of life; “an obligate anaerobe can survive only in the absence of oxygen”
International Coffee Day (September 29) is an occasion to promote and celebrate coffee as a beverage, with events occurring in places across the world. A day to promote fair trade coffee and raise awareness for the coffee growers’ plight. Other countries celebrate this event on October 1.
