Definitions of nucleus:

  • noun:   a part of the cell containing DNA and RNA and responsible for growth and reproduction
  • noun:   any histologically identifiable mass of neural cell bodies in the brain or spinal cord
  • noun:   the positively charged dense center of an atom
  • 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
  • noun:   a small group of indispensable persons or things