peek-a-boo
UK[ˌpiːk ə ˈbuː]US[ˌpiːk ə ˈbuː]
n
A game played with a young child in which you hide your face and then suddenly show it again, saying "peek-a-boo!"
adj
(of clothing) made of a very thin or open fabric that reveals the skin or an undergarment.
Etymology
The term "peek-a-boo" is a classic example of a nursery word, emerging in English in the late 16th century. It is formed through a playful, rhythmic reduplication of the verb "peek" (meaning to look quickly or furtively) and the exclamation "boo" (used to surprise someone). The logic of the game is embedded directly in the phonetics of the word: "peek" represents the moment of looking, while the altered, rhyming "boo" represents the sudden revelation and accompanying sound. This onomatopoeic and mimetic formation bypasses traditional etymology, instead evolving from the universal parent-child interactions that give rise to baby talk across languages.
Analysis
This is a reduplicative compound, formed by the playful combination and alteration of the verb "peek" and the exclamation "boo." It is not productively built from classical morphemes.
Examples
The baby giggled with delight during a game of peek-a-boo.
She wore a peek-a-boo lace top over a camisole.
Playing peek-a-boo helps infants develop object permanence.