Longman Dictionary of Contemporary English - hat

~ n 1 a piece of clothing that you wear on your head  (straw/bowler/woolly etc hat)  (She wore an enormous flowery hat.) 2 keep something under your hat informal to keep something secret 3 be wearing your manager's/teacher's etc hat informal to be doing your duty as a manager etc, which is not your only duty 4 I take my hat off to informal used to say you admire someone very much because of what they have done 5 pass the hat round BrE /pass the hat (around) AmE to collect money from a group of people, especially in order to buy someone a present 6 bowler-hatted/top-hatted etc wearing a bowler hat, etc 7 my hat! old-fashioned used to express great surprise  (- see also hard hat, at the drop of a hat drop2 (5), hang up your hat hang1 (14), I'll eat my hat eat (10), old hat, be talking through your hat talk1 (17), throw your hat into the ring throw1 (33))