Nucleus

What does NUCLEUS mean?

1. noun

   a part of the cell containing DNA and RNA and responsible for growth and reproduction

2. noun

   the positively charged dense center of an atom

3. noun

   a small group of indispensable persons or things

   “five periodicals make up the core of their publishing program”

4. 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

Definitions from WordNet 3.1, Princeton University.