cap

¹cap

noun, often attrib \ˈkap\

Definition of CAP

1

: a natural cover or top: as a : pileus b : patella, kneecap

2

: something that serves as a cover or protection especially for a tip, knob, or end (as of a tooth)

3

British : cervical cap

4

: a cluster of molecules or chemical groups bound to one end or a region of a cell, virus, or molecule <the cell surface receptors were redistributed into caps>