\ ˈslī How to pronounce sly (audio) \
slyer also slier\ ˈslī(-​ə)r How to pronounce slier (audio) \; slyest also sliest\ ˈslī-​əst How to pronounce sliest (audio) \

Definition of sly

1 chiefly dialectal

a : wise in practical affairs
b : displaying cleverness : ingenious
2a : clever in concealing one's aims or ends : furtive
b : lacking in straightforwardness and candor : dissembling
3 : lightly mischievous : roguish a sly jest
on the sly
: in a manner intended to avoid notice

Keep scrolling for more

Other Words from sly

slyly or less commonly slily adverb
slyness noun

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 list of movies coming out in July 2019 is a veritable tour of the currently Hollywood landscape: a good balance of light-hearted flicks, action-packed hits, and a few movies with sly awards season potential. Ariana Brockington,, "The Best New Movie Releases In July 2019, From Spider-Man To The Next Hereditary," 5 July 2019 After banging home a bad clearance in the 11th minute, Lloyd hugged a few teammates and then, with a sly grin, gave a small golf clap. Nancy Armour, USA TODAY, "Opinion: US women aren't backing off at World Cup," 16 June 2019 His demand that Watts’s Carlson do a twirl in the hallway — and her sly submission to it — are disturbing. Matthew Gilbert,, "Russell Crowe a force as Roger Ailes in ‘The Loudest Voice’," 26 June 2019 With some sly self-promotion, Uslan's popular class became the subject of much media coverage. Scott Huver, CNN, "'Batman' turns 30: How a superfan got Hollywood to redefine the Dark Knight," 23 June 2019 As the crowd divided into two teams, on the grounds of James Fenimore Cooper’s garden in Cooperstown, New York, this gave Lexington a sly advantage. The Economist, "Baseball and exceptionalism," 8 June 2019 The film is elevated by Ms. Danner’s quicksilver presence, and leavened by Ms. Chomko’s sly sense of humor and lyrical sense of loss. Joe Morgenstern, WSJ, "‘What They Had’ Review: A Troubled Trip Down Memory Lane," 18 Oct. 2018 Soccer is such a low-scoring sport by comparison with others that the margins for success and failure are particularly small; this means that acts of gamesmanship—a sly foul here, a cunning dive there—can be especially pivotal. Musa Okwonga, Quartz Africa, "How to make the case for and against VAR—video assistant referee—in the beautiful game," 10 June 2019 From Google's sly tricks to Twitter's wacky gags, here's a roundup of the Internet's most popular practical jokes of April 1st, 2013. Amanda Montell, Woman's Day, "Spilling the Beans on Today's Top April Fool's Day Pranks," 1 Apr. 2013

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sly.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of sly

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

History and Etymology for sly

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

Keep scrolling for more

Learn More about sly

Dictionary Entries near sly






sly goose


Statistics for sly

Last Updated

15 Jul 2019

Look-up Popularity

Time Traveler for sly

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

See more words from the same century

Keep scrolling for more

More Definitions for sly



English Language Learners Definition of sly

: clever in a dishonest way
: showing that you know a secret


\ ˈslī How to pronounce sly (audio) \
slier or slyer; sliest or slyest

Kids Definition of sly

1 : both clever and tricky
2 : tending to keep secrets and hide intentions
3 : mischievous sense 2 There were teachers all over the place, and any kind of fighting or taunting, above a sly pinch … was out.— Lynne Reid Banks, The Indian in the Cupboard
on the sly
: so as not to be seen or caught : secretly

Other Words from sly

slyly adverb
slyness noun

Keep scrolling for more

More from Merriam-Webster on sly

Thesaurus: All synonyms and antonyms for sly

Spanish Central: Translation of sly

Nglish: Translation of sly for Spanish Speakers

Britannica English: Translation of sly for Arabic Speakers

Comments on sly

What made you want to look up sly? Please tell us where you read or heard it (including the quote, if possible).


an act or instance of editing or removing

Get Word of the Day daily email!

Test Your Vocabulary

What's that Smell?! Quiz

  • wide eyed dog smelling rose
  • Someone who is hircine smells like a:
Name That Thing

Test your visual vocabulary with our 10-question challenge!


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!