- (disapproving) acting or done in a secret or dishonest way, often intending to trick people synonym cunning
- a sly political move
- (humorous) You sly old devil! How long have you known?
- She’s a sly one—never lets on what she’s thinking.
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- [usually before noun] suggesting that you know something secret that other people do not know synonym knowing
- a sly smile/grin
Word OriginMiddle English (also in the sense ‘dexterous’): from Old Norse slœgr ‘cunning’, originally ‘able to strike’ from the verb slá.
Idioms
See sly in the Oxford Advanced American Dictionaryon the sly
- secretly; not wanting other people to discover what you are doing
- He has to visit them on the sly.
Check pronunciation:
sly