also peek-a-boo, as the name of a children's game attested from 1590s; as an adjective (of garments) meaning "see-through, open," it dates from 1895. From peek (v.) + boo. Compare bo-peep.
pedophiliac
pedophilic
peduncle
pee
peek
peekaboo
peel
peeler
peen
peep
peeper