peekaboo (n.)
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.
Who started peekaboo?
Psychologist Jean Piaget conducted experiments with infants which led him to conclude that this awareness was typically achieved at eight to nine months of age. He claimed that infants before this age are too young to understand object permanence.
What does peekaboo mean?
exclamation, noun [ U ] /ˈpik·əˌbu/ a game played with very young children in which you hide your face, esp. with your hands, and then suddenly take your hands away, saying "peek-a-boo"
