A set of four basic biological instincts: feeding, fighting, fleeing, and fucking.

(sports) The semifinal.

(cricket) The batsman who bats fourth.

Having four eyes. / (slang, chiefly derogatory) Wearing spectacles.

Alternative spelling of four-on-the-floor

Alternative form of Gang of Four

(attributive, of a transmission) Having four forward speeds. / A vehicle with a transmission that has four forward speeds. It might or might not be a manual transmission.

Alternative form of four of a kind

(restaurants) A table seating four diners.

plural of four-top