1a kind of soft, flat hat without a brim and typically with a peak:a man wearing a raincoat and a flat cap figurativeher cap of dark hair
[with adjective or noun modifier] a kind of soft, close-fitting head covering worn for a particular purpose:a shower capa bathing cap
British a cap awarded as a sign of membership of a particular sports team, especially a national team:he has won three caps for Scotland
British a player to whom a cap is awarded:a former naval officer and rugby cap
an academic mortar board:school-leavers in cap and gown
2a protective lid or cover for an object such as a bottle, the point of a pen, or a camera lens:a glass bottle with a screw capa lens cap from a camera
an artificial protective covering for a tooth.
the top of a bird’s head when distinctively coloured.
3an upper limit imposed on spending or borrowing:he raised the cap on local authority spending
4 (also Dutch cap)British informal a contraceptive diaphragm.
5the broad upper part of the fruiting body of most mushrooms and toadstools, at the top of a stem and bearing gills or pores.