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
animal reproductive body consisting of an ovum or embryo together with nutritive and protective envelopes; especially the thin-shelled reproductive body laid by e.g. female birds
oval reproductive body of a fowl (especially a hen) used as food
the central part of a car wheel (or fan or propeller etc) through which the shaft or axle passes
a center of activity or interest or commerce or transportation; a focal point around which events revolve; "the playground is the hub of parental supervision"; "the airport is the economic hub of the area"