1.a band, while during any time in their existance, has only one song achieve the 'hit' status. after which, they fizzle out and disappear, never following up their initial success
2.(lesser used def.)a girl/guy, who is not sexually desirable, but gets a piece of your ass via intoxication, low light, etc.
1.the Crash Test Dummies were a one-hit wonder.
2. Man, why'd you grind that chick? She was fuckin ugly! Yeah, it was a one-hit wonder.