keep under one's hat

Preserve the secrecy of something, as in I'll tell you about it if you promise to keep it under your hat. This usage alludes to hiding a secret in one's head, covered by a hat. [Late 1800s]

Common Names:

Name	Pronounced	Usage
Andreea	ahn-DRE-ah	Romanian
Manlius	-	Ancient Roman
Toma (2)	TO-mah (Croatian, Serbian)	Romanian, Croatian, Serbian, Bulgarian, Macedonian, Georgian
Stijn	STIEN	Dutch
RosÁLia	roo-ZA-lyə	Portuguese
Pratik	-	Indian, Hindi, Marathi, Gujarati, Bengali