any of the elementary particles having a mass equal to or greater than that of a proton and that participate in strong interactions; a hadron with a baryon number of +1
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