The massive, positively charged central part of an atom made up of protons and neutrons.
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
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
the central structure of the lens that is surrounded by the cortex
