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