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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.

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

From The Wall Street Journal • Nov. 30, 2025

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

When Burnett was growing up in Brooklyn, dancing was something he had to do on the sly.

From New York Times • Jul. 23, 2021

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

From "Bronx Masquerade" by Nikki Grimes

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