(dated, idiomatic) In quick succession, or in great numbers.

(nautical) All plank that is more than four inches thick and less than twelve.

(UK, historical, obsolete slang) A crown coin; its value, five shillings.

plural of thick-un

(informal, Hiberno-English) Very ignorant or foolish, sullen or in a bad temper.

Alternative form of thick as pig shit

(computing) Synonym of fat client

plural of thick client

(simile, Scotland) Very stupid

(chiefly Britain, dated) High tea or an informal late afternoon or early evening meal, more substantial than afternoon tea. / Used other than figuratively or idiomatically: see thick, tea.