An onomatopoeic adverb for a fleeting glance or a brief, fleeting appearance; indicates a quick, slight action.
彼女はドアの隙間からチラリと外を見た。
She took a quick peek outside through the gap in the door.
スピーチ中、彼は聴衆をチラリと見ただけで続けた。
During the speech, he only glanced at the audience briefly and continued.
猫がチラリと顔を出して、また隠れた。
The cat poked its head out briefly and then hid again.