To peek or peep (to look secretly or briefly, e.g., through a gap or keyhole).
子どもが穴から外を覗き見ると、猫が通りを歩いていた。
When the child peeked outside through the hole, a cat was walking down the street.
試験中に隣の答案を覗き見るのはルール違反だ。
Peeking at the neighbor's answers during an exam is against the rules.
カメラで覗き見るように画面を確認した。
I checked the screen as if peeking through a camera viewfinder.