Definition of 'nucleus'
- a part of the cell containing DNA and RNA and responsible for growth and reproduction
Synonyms: cell nucleus karyon
- the positively charged dense center of an atom
- a small group of indispensable persons or things; "five periodicals make up the core of their publishing program"
Synonyms: core core group
- (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
- any histologically identifiable mass of neural cell bodies in the brain or spinal cord