1. Announce the sale of an object costing one dollar and fifty cents.
2. Be a synonym for male genitalia.
Clerk: That'll be a dolla fitty.
You: How much?
Clerk: A dolla fitty.
You: All right.
Friend: Hey, see that girl over there? Bet you won't ask her out.
You: Ha, I'll do more than that. I'll give her a dolla fitty tonight.
Friend: Oh man, tell me about it tomorrow!