PU or P.U. pronounced pue, peuh, peugh, pyoo, pu, and pew; is an interjection used to express contempt, disgust, or derision, often because of a smell or odor . It is usually pronounced "pew!" or "pee-you!"
I think you mean "Pee-eww", it is a phrase used as an interjection (a word meaning to convey emotion) when something smells, e.g "pee-eww, that place smells"
agreed its more of a sound than it is a word.
agreed its more of a sound than it is a word.