Definition from Wiktionary, the free dictionary
- (idiomatic) Something that discloses, usually unintentionally, a fact or an intention.
- That disguise is a dead giveaway! Choose something less obvious.
- 2008, New York Times, March 5
- "Instead of slowing down his arm when he throws it — a dead giveaway to hitters — Igawa had better arm action, Eiland said"
- tell (noun)