ˈ ̷ ̷ˌkap noun
1.
a. : the male of the European redstart
b. Britain : whitethroat 1
c. : tree sparrow 1
2. : a wave crest breaking into white foam
3.
a. : horse mushroom
b. : hardhack 1
4.
a. : one who wears a white cap
b. also white·cap·per -pə(r) usually capitalized : a member of a group using a white cap as an identifying badge ; especially : one of a self-appointed vigilance committee attempting by lynch-law methods to drive away or coerce persons obnoxious to it