sly

adjective

ˈslī 

slyer also slier ˈslī(-ə)r  ; slyest also sliest ˈslī-əst 

1

chiefly dialectal

a

: wise in practical affairs

b

: displaying cleverness : ingenious

2

a

: clever in concealing one's aims or ends : furtive

b

: lacking in straightforwardness and candor : dissembling

3

: lightly mischievous : roguish

a sly jest

slyly adverb

or less commonly slily

She slyly evaded the question.

slyness noun

see also:

on the sly

Synonyms of sly

• cunning
• cute
• subtle
• slick

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

The shift away from reliability suggests a sly reversal of sympathies from the artist to the do-gooder sibling. —Elaine Blair, Harpers Magazine, 24 Feb. 2026

Consider Aspen, an exploration of the Colorado resort community that sees Wiseman balance his respect for the town’s palatial beauty and the workers tasked with its upkeep with his sly contempt for the wealthy denizens treating the town like their playground. —Vikram Murthi, The Atlantic, 22 Feb. 2026

Tushtu, the meekest, frailest of the chanters, trailing at the back, stopped to turn towards Charu with a sly grin. —Literary Hub, 19 Feb. 2026

The sly blend of beauty and brutality is also apparent in the film’s sound design. —Patrick Brzeski, HollywoodReporter, 14 Feb. 2026

Word History

Etymology

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

Rhymes for sly

• ai
• aye
• bae
• bi
• buy
• by
• bye
• chai
• chi
• cry
• die
• dry

Kids Definition

sly

adjective

ˈslī 

slier or slyer ˈslī(-ə)r  ; sliest or slyest ˈslī-əst 

1

a

: clever at hiding one's goals or purpose

b

: tending to secrecy or concealment

2

: lightly mischievous

a sly smile

slyly adverb

slyness noun