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Meaning of NUCLEUS

Pronunciation:  'nookleeus

WordNet Dictionary
  1. [n]  a part of the cell containing DNA and RNA and responsible for growth and reproduction
  2. [n]  any histologically identifiable mass of neural cell bodies in the brain or spinal cord
  3. [n]  a small group of indispensable persons or things; "five periodicals make up the core of their publishing program"
  4. [n]  the positively charged dense center of an atom
  5. [n]  (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

NUCLEUS is a 7 letter word that starts with N.


 Synonyms: cell nucleus, core, core group, karyon
 See Also: achromatin, atom, cadre, cell, cell organ, center, centre, chromatin, chromosome, comet, karyoplasm, midpoint, neural structure, nucleole, nucleolus, nucleon, nucleoplasm, organelle, pronucleus, set



Webster's 1913 Dictionary
\Nu"cle*us\, n.; pl. E. {Nucleuses}, L. {Nuclei}. [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

         It must contain within itself a nucleus of truth.
                                               --I. Taylor.

2. (Astron.) 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.) 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. (Zo["o]l.)
   (a) The tip, or earliest part, of a univalve or bivalve
   (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.

Medical Dictionary
 Definition: Center portion of cells essential for cell growth, nourishment and reproduction.
Biology Dictionary
 Definition: The cellular organelle in eukaryotes that contains the genetic material. Diameter is usually 5 micrometers. Plural: nuclei.
  1. The membrane-bound region of a eukaryotic cell that contains the chromosomes.
  2. The cellular organelle in eukaryotes that contains most of the genetic material.
  3. a structure found in the cell that contains the chromosomes.
Thesaurus Terms
 Related Terms: alpha particle, Anlage, antibaryon, antilepton, antimeson, atomic nucleus, atomic particle, axiom, axis, baryon, basichromatin, beta particle, bud, center, center of action, center of gravity, centroid, centrum, chromatin, chromatin strands, core, dead center, diameter, diaphragm, egg, electron, elementary particle, elixir, embryo, epicenter, equator, essence, essential, flower, focus, fundamental, germ, germen, gist, gravamen, heart, heterochromatin, hub, hypostasis, inner essence, interior, karyosome, karyotin, Kern, kernel, lepton, loins, macronucleus, marrow, mean, meat, median, medulla, meganucleus, meson, metacenter, micronucleus, middle, midmost, midriff, midst, nave, navel, neutron, NMR, nub, nuclear force, nuclear magnetic resonance, nuclear particle, nuclear resonance, nucleolus, nucleon, nucleosynthesis, nuts and bolts, omphalos, ovum, photon, pith, pivot, plasmosome, postulate, principle, proton, quid, quiddity, quintessence, rudiment, sap, seed, soul, spark, spermatozoon, spirit, storm center, strangeness, strong interaction, stuff, substance, the nitty-gritty, thick, thick of things, triton, umbilicus, valence electron, waist, waistline, zone