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 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
the quality of being significant; "do not underestimate the significance of nuclear power"
a meaning that is not expressly stated but can be inferred; "the significance of his remark became clear only later"; "the expectation was spread both by word and by implication"