Definition of sly
- a sly jest
the movie pairs a sly, dissembling ex-con with an upstanding, straight-arrow cop
why, you sly fellow! I had no idea you were planning my birthday party
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sly.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
: clever in a dishonest way
: showing that you know a secret
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