keep something under your hat
成語所屬單字hat
keep something under your hat — 慣用語
1. to keep a piece of information secret and not tell anyone else about it.
1.慣用語
釋義
保守秘密
to keep a piece of information secret and not tell anyone else about it.
例句
Keep this news under your hat until the company makes its official statement.
I know who won the award, but I promised to keep it under my hat.