slyer also slier ˈslī(-ə)r How to pronounce sly (audio) ; slyest also sliest ˈslī-əst How to pronounce sly (audio)
chiefly dialectal
: wise in practical affairs
: displaying cleverness : ingenious
: clever in concealing one's aims or ends : furtive
: lacking in straightforwardness and candor : dissembling
: lightly mischievous : roguish
a sly jest
slyly adverb
or less commonly slily
She slyly evaded the question.
slyness noun
on the sly
: in a manner intended to avoid notice
Choose the Right Synonym for sly

sly, cunning, crafty, wily, tricky, foxy, artful, slick mean attaining or seeking to attain one's ends by guileful or devious means.

sly implies furtiveness, lack of candor, and skill in concealing one's aims and methods.

a sly corporate raider

cunning suggests the inventive use of sometimes limited intelligence in overreaching or circumventing.

the cunning fox avoided the trap

crafty implies cleverness and subtlety of method.

a crafty lefthander

wily implies skill and deception in maneuvering.

the wily fugitive escaped the posse

tricky is more likely to suggest shiftiness and unreliability than skill in deception and maneuvering.

a tricky political operative

foxy implies a shrewd and wary craftiness usually involving devious dealing.

a foxy publicity man planting stories

artful implies indirectness in dealing and often connotes sophistication or cleverness.

elicited the information by artful questioning

slick emphasizes smoothness and guile.

slick operators selling time-sharing

Examples of sly in a Sentence

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
Recent Examples on the Web But pay close attention to what’s happening on screen and there is a sly and markedly witty humor that underscores (pun intended) the film. Lily Moayeri, SPIN, 9 Feb. 2024 Some were precise and academic, but many were sly and droll. Jason Farago, New York Times, 11 Jan. 2024 Andrew grew into a gangly teenager with a sly sense of humor who wore braces, dyed his hair bright colors and swept his long bangs across his face. Kathleen McGrory, ProPublica, 6 Jan. 2024 Through this sly trick, where doorknobs rise to noses and walls tower high above the hairline, Argento sketches a vision of witchy terror akin to early works of German surrealism. Declan Gallagher,, 23 Oct. 2023 Workman has won awards as a comic, and there’s a sly humor wound throughout Aberdeen’s shadows. Sara Holdren, Vulture, 3 Feb. 2024 Glover and Erskine are best known for their comedy work, and there’s a lot of sly humor to be found in the emotional clashes between the two. Alan Sepinwall, Rolling Stone, 1 Feb. 2024 The media figures who peddle extremism to the public, Kayyem added, employ sly tactics to shield themselves from accountability when a perpetrator acts on their words. Oliver Darcy, CNN, 1 Feb. 2024 Jose Miranda Hubris isn’t a long or super-complex show, but there’s an abundance of sly poignancy within its simple frame. Sara Holdren, Vulture, 25 Jan. 2024 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'sly.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Middle English sleighe, sli, from Old Norse slœgr; akin to Old English slēan to strike — more at slay

First Known Use

13th century, in the meaning defined at sense 1a

Time Traveler
The first known use of sly was in the 13th century

Dictionary Entries Near sly

Cite this Entry

“Sly.” Dictionary, Merriam-Webster, Accessed 25 Feb. 2024.

Kids Definition


slier or slyer ˈslī(-ə)r How to pronounce sly (audio) ; sliest or slyest ˈslī-əst How to pronounce sly (audio)
: clever at hiding one's goals or purpose
: tending to secrecy or concealment
: lightly mischievous
a sly smile
slyly adverb
slyness noun

More from Merriam-Webster on sly

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