Nuclei

3 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Nucleus \Nu"cle*us\, n.; pl. E. {Nucleuses}, L. {Nuclei}. [L., a
     kernel, dim. fr. nux, nucis, nut. Cf. {Newel} post.]
     [1913 Webster]
     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.
        [1913 Webster]
  
              It must contain within itself a nucleus of truth.
                                                    --I. Taylor.
        [1913 Webster]
  
     2. (Astron.) The body or the head of a comet.
        [1913 Webster]
  
     3. (Bot.)
        (a) An incipient ovule of soft cellular tissue.
        (b) A whole seed, as contained within the seed coats.
            [1913 Webster]
  
     4. (Biol.) A body, usually spheroidal, in a eukaryotic cell,
        distinguished from the surrounding protoplasm by a
        difference in refrangibility and in behavior towards
        chemical reagents, which contains the chromosomal genetic
        material, including the chromosomal DNA. 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}.
        [1913 Webster +PJC]
  
     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}.
           [1913 Webster]
  
     5. (Zool.)
        (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.
            [1913 Webster]

From WordNet (r) 2.0 [wn]:

  nucleus
       n 1: a part of the cell containing DNA and RNA and responsible
            for growth and reproduction [syn: {cell nucleus}, {karyon}]
       2: the positively charged dense center of an atom
       3: a small group of indispensable persons or things; "five
          periodicals make up the core of their publishing program"
          [syn: {core}, {core group}]
       4: (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
       5: any histologically identifiable mass of neural cell bodies
          in the brain or spinal cord
       [also: {nuclei} (pl)]

From WordNet (r) 2.0 [wn]:

  nuclei
       See {nucleus}