(meteorology) An accessory cloud in the form of a cap which occurs above, or attached to, cumulus, cumulonimbus, and sometimes stratocumulus clouds.

Alternative spelling of kneecap

A market-based approach to control pollution by providing economic incentives for achieving reductions in emissions, participating companies being assigned an emissions quota that can be traded with others if not used.

Any of various originally military caps intended for undress or working use.

A round shaped tight-fitted cap worn by brides etc.

a metal cap found on muzzleloading firearms that contains chemical substances such as fulminate that explode upon impact

A parasitic fungus, Asterophora lycoperdoides, that lives on other mushrooms.

(photography) The detachable cap that protects the camera lens when the camera is not in use.

A display of goods for sale situated at an end of an aisle in a shop, perpendicular to the goods in the aisle.

Alternative spelling of cross-cap