ˈhat-block [See block n. 4 a.] A form or mould upon which a man's hat is shaped. Hence hat-block maker, hat-block turner. 1723Lond.Gaz.No. 6192/9 Thomas Bossworth..Hat-Block Turner.1858Simmonds Dict. Trade, Hat-block maker, a manufacturer of the solid wooden shapes used in blocking or forming hats.