keep under your hat

Meaning

1. Oxford100% of films

   to keep sth secret and not tell anyone else

   But, uh, keep it under your hat, hmm?

   Listen, uh, keep this under your hat, will you?

In the movies · 3

• Keep it under your hat. [Sighs] The people they need, like scientists. You heard about that?Slacker1990
• But, uh, keep it under your hat, hmm?Withnail & I1987
• Listen, uh, keep this under your hat, will you?White Christmas1954
• Keep it under your hat, huh?Lucky Number Slevin2006

Learn it in full scenes

• Slacker1990
  • The Dreamer Explains His Reality Theory
  • A Man Dictates The Gambler
  • The Moon Landing Was a Cover-Up

From the same entry

• go hat in hand
• my hat
• out of a hat
• I take my hat off to
• throw your hat into the ring
• at the drop of a hat
• I'll eat my hat
• knock into a cocked hat
• pass the hat round
• pull rabbit out of the hat
• talk through your hat