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Synonyms

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]


Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

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

From The Wall Street Journal ● Nov. 30, 2025

Opening the case, prosecutor Naeem Valli said Connolly also sent a message saying she intended to work her notice period as a childminder "on the sly" - despite being de-registered.

From BBC ● Oct. 17, 2024

Show up to volunteer and Ignazio Vivirito, 83, who is always cooking something, might slip you a fresh-baked biscotti or a snack of bread and cheese on the sly.

From Los Angeles Times ● Jun. 14, 2023

You started taking hormones kind of on the sly for a couple of weeks before you even talked to your wife.

From Slate ● Jun. 2, 2023

Do my thoughts trade places like letters, on the sly?

From "Bronx Masquerade" by Nikki Grimes

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