OUCH!
The word ouch is not a noun; ouch is an interjection, a exclamation of sharp sudden pain.
Crash is a 5-letter word that can refer to "a sudden noise".
A three letter synonym for the exclamation 'gosh' is gee.
A one or two-word exclamation is called an "interjection." Interjections are words or phrases that express strong emotion or sudden bursts of feeling, often standing alone. Examples include "Wow!" or "Oops!"
The vowel sound is the same as the exclamation of pain 'ow!' or the exclamation 'wow!'.
cramps
Skoal
onrush
craving
Sudden
Unexpected
fervent