1. a shaped covering for the head worn for warmth, as a fashion item, or as part of a uniform: "a black straw hat"
▪ used to refer to a particular role or occupation of someone who has more than one:"wearing her scientific hat she is director of a pharmacology research group"
Word OriginOld Englishhætt, of Germanic origin; related to Old Norse hǫttr ‘hood’, also to hood1.