also: うわー · うわっ · うわあ
An exclamation of surprise, shock, dismay, or sudden realization. The exact nuance depends on tone and context; can express anything from mild alarm to genuine fright.
Whoa, you startled me!
Oops, I messed up…
Basic kana form; no kanji spelling exists.
Abrupt variant with a glottal stop, often for sudden shock.
Drawn-out variant for emphasis.
Lengthened variant expressing stronger emotion.
A natural exclamation; the exact origin is uncertain, but it is likely a spontaneous vocalization of surprise or distress.