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

plural of thick-un

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

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

plural of thick client

(computing) Synonym of fat client

(simile, Scotland) Very stupid

Alternative form of thick as pig shit

(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.

plural of thick tea