PEEKABOO
peekaboo, bopeep
(noun) a game played with young children; you hide your face and suddenly reveal it as you say boo!
Source: WordNet® 3.1
Etymology
Noun
peekaboo (uncountable)
(games) A game for a small child in which one covers one's face, then suddenly reveals it, saying "Boo!" or "Peekaboo!".
Adjective
peekaboo (not comparable)
(of clothing) with holes, slits or transparent fabric to reveal what is normally hidden.
Verb
peekaboo (third-person singular simple present peekaboos, present participle peekabooing, simple past and past participle peekabooed)
(intransitive) To peep out.
Interjection
peekaboo
boo (when showing oneself unexpectedly)
Source: Wiktionary
Peek"a*boo, n.
Definition: A child's game; bopeep.
Source: Webster’s Unabridged Dictionary 1913 Edition