on the sly

Idioms  

1. Furtively, secretly, as in She's always eating cookies on the sly. The adjective sly, which means “cunning” or “crafty,” is here used as a noun. [c. 1800]

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Example Sentences

The math-proficiency analysis suggests it may be doing so on the sly.

From The Wall Street Journal

“They want me to go in with them on the sly,” says Colonel Sellers, the anti-hero of that novel.

From Salon

We were forbidden to speak Urdu, but my mother still taught us on the sly.

From New York Times

He was paroled from detention but banned from work and national health insurance, though he worked on the sly until about eight years ago, when the government started to tighten controls over parolees.

From Los Angeles Times

You steal work from US writers on the sly, and you're blacklisted.

From Los Angeles Times

Related Words

• clandestinely
• covertly
• furtively
• personally
• privately
• quietly
• stealthily
• surreptitiously