A large, naturally-occurring cavity formed underground or in the face of a cliff or a hillside. / A hole, depression, or gap in earth or rock, whether natural or man-made.

To surrender. / To collapse. / To hollow out or undermine. / To engage in the recreational exploration of caves.

(Britain, school slang) look out!; beware!

(intransitive) To criticise for petty or frivolous reasons.

A petty or trivial objection or criticism.

Not caring enough about something important. / High-spirited. / Supercilious. / (historical) Of or pertaining to the party of King Charles I of England (1600–1649).

(historical) A military man serving on horse, (chiefly) early modern cavalry officers who had abandoned the heavy armor of medieval knights.

(transitive, dated) Of a man: to act in a gallant and dashing manner toward (women).

A hole or hollow depression in a solid object. / (anatomy) A hollow area within the body.

(anatomy) The cavity of the mouth, especially the part of the mouth behind the gums and teeth that is bounded above by the hard and soft palates and below by the tongue and by the mucous membrane connecting it with the inner part of the mandible.