dead giveaway

something that reveals a fact or an intention completely. The car in the driveway was a dead giveaway that someone was at home.

Name	Pronounced	Usage
Thijs	TIES	Dutch
Aleck	['ælik]
Clayton	['kleitn]
Tessa	TES-ə	English
Andre	awn-DRAY	English, African American
Kallisto	-	Greek Mythology, Ancient Greek