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
Eutropia	-	Ancient Greek
Ally (1)	AL-ee	English
Bysshe	BISH	English (Rare)
Ewald	E-vahlt (German)	German, Dutch, Ancient Germanic
Filippo	-	Italian
Lake	[leik]