sly

American  

[slahy] / slaɪ /

adjective

comparative

slyer, slier,

superlative

slyest, sliest

1. cunning or wily.

   sly as a fox.

   Synonyms:

   astute, shrewd, crafty, foxy, subtle, artful

   Antonyms:

   obvious, direct

2. stealthy, insidious, or secret.

   Synonyms:

   clandestine, underhand, furtive, surreptitious

3. playfully artful, mischievous, or roguish.

   sly humor.

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idioms

1. on the sly, secretly;

   a tryst on the sly.

sly British  

/ slaɪ /

adjective

1. crafty; artful

   a sly dodge

2. insidious; furtive

   a sly manner

3. playfully mischievous; roguish

   sly humour

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noun

1. in a secretive manner

sly More Idioms  

1. see on the sly.

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Other Word Forms

• slyly adverb
• slyness noun
• unsly adjective
• unslyly adverb
• unslyness noun

Etymology

Origin of sly

First recorded in 1150–1200; Middle English sly, sley , from Old Norse slœgr “sly, cunning” (originally “able to strike, able to slay”); slay ( def. )

Example Sentences

Weir’s playing was nimble and intuitive, his voice a sly croon that got appealingly craggy with age.

From Los Angeles Times

Here, it is a man whose labor disappears behind a woman’s byline, a sly inversion of the far more familiar historical pattern.

From Salon

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

From The Wall Street Journal

But Dougal’s naiveté does not preclude a sly sense of humor.

From The Wall Street Journal

The young trio’s minimalist arrangements evoke the clang of downtown post-punk New York, while the new collection’s sly humor and deep well of hooks helped the dissonant turns go down easily.

From The Wall Street Journal

Related Words

• canny
• impish
• ingenious
• intriguing
• mischievous
• roguish
• shrewd
• smart
• subtle