Other forms: peeks, peeking, peeked
To peek is to take a quick look you probably should not. Through a gap in the curtains, round the edge of a door, at the last page of a book before you get there.
It is a noun as well: take a peek, have a peek, a sneak peek at something before everyone else sees it. It nearly always takes a preposition — peek at your cards, peek through the fence, peek into the box, peek over the wall. Things peek out on their own too: the sun peeked out from behind a cloud, a label peeking out of a collar. Peep means much the same and is the older word; peek is what people reach for now. Three spellings share the sound and none of them mean this — peak is a mountain top, pique is wounded pride, and piqued is what your curiosity gets.
1verbpeekTo look quickly and secretly at something.
“She peeked at the price on the back of the box.”
2verbviewTo come partly into view.
“The sun peeked out from behind the clouds for a minute.”
3nounglimpseA quick, secret look.
“Take a peek inside before I wrap it.”
peek is a quick look.
Also accepted in games: peep
Peek looks like two words that fell into each other. Middle English had pepen, to peep, and keken, to keek — an old word for looking and spying — and peken seems to be the pair of them fused. English still keeps peep and keek as separate words, with peek sitting between them.
Middle English
*peken
English, today
peek
Built from
From Middle English peken, piken, pyken (“to peep”), probably a fusion of Middle English pepen (“to peep”) and keken, kiken (“to keek, look, spy”), equivalent to a peep and keek. Perhaps also possibly a metathetic alteration of kepen, kipen, kypen (“to keep, look, observe, watch”).
Etymology from Wiktionary, CC BY-SA
Practised in Everyday Verbs, Ways of Looking