Definition of sly in English:



  • 1Having or showing a cunning and deceitful nature.

    ‘she had a sly personality’
    • ‘He was cunning, sly and a good strategist, beating her at games of wits when others can't.’
    • ‘Lord knows the girl had made enough sly remarks about them getting together.’
    • ‘Ray was oblivious to my cunning and sly plan, and I kept it that way.’
    • ‘How could he have forgotten how sly and deceitful Viya was?’
    • ‘These bungalows had their own world, their own parties and picnics, their special sly and subtle ‘in’ jokes.’
    • ‘She was a rather cunning and sly teenager by nature, accented by her narrow brown eyes and usual smirk.’
    • ‘Those raised in urban Western understanding of the psychology of the animal kingdom tend to view the fox as a cunning, sly, deceitful animal.’
    • ‘When Chinese describe a person as ‘a monkey’, it means the person is extremely sly or cunning.’
    • ‘The dialogue is often artful, with sly suggestions that the seeds of various Shakespearean plots and themes were sown in the muck of their messy affair.’
    • ‘Her letters therefore reveal a web of motives and sly manipulation that her uncomfortable position encouraged.’
    • ‘It's not impossible that such a conspiracy is taking place, because there are many sly people who manipulate the dumb citizens for their own benefit.’
    • ‘I'm starting to go faster at each race but I'm still not sly enough when it comes to hitting my adversaries!’
    • ‘Diplomacy as a game values the sly, the cunning, the underhanded, the crafty.’
    • ‘If the character feels angry, I go crazy; and it's the same with sadness, but with the Marquise, she is sly and calculating and that's my hardest challenge.’
    • ‘His character is a blending of many different traits: he's smart, sly, manipulative, dangerous, and much more.’
    • ‘But it is dispensed with such style, coupled to such a mixture of absurd silliness and sly knowingness about human nature, that you can't help falling for its charms.’
    • ‘The Romans, who will resolutely overwhelm an adversary with the might of arms, they say Phoenicians are deceitful and sly.’
    • ‘It is sly, clever after a fashion, and undeniably effective.’
    • ‘She'd obviously met a bad bunch, for McCabe is immoral, deceitful and sly.’
    cunning, crafty, clever, wily, artful, guileful, tricky, conniving, scheming, devious, designing, deceitful, duplicitous, dishonest, disingenuous, underhand, sneaky, untrustworthy
    View synonyms
    1. 1.1 (of a remark, glance, or facial expression) showing in an insinuating way that one has some secret knowledge that may be harmful or embarrassing.
      ‘he gave a sly grin’
      • ‘‘We may let in a few goals,’ he said with a sly grin.’
      • ‘But that short eyebrow, sly grin and crooked jaw are now what make me, well, me.’
      • ‘Given his reluctance to admit the obvious, it's no surprise he still manages to aim a selection of sly digs at the Australian umpires and authorities.’
      • ‘By delivering her message with a sly grin, West reminded us that sex - and, by extension, life - is supposed to be fun.’
      • ‘Oozing grace, charm, wit and style, she gives a masterclass of the English mannered style - a raised eyebrow here or a sly grin there sufficient to keep us engaged.’
      • ‘The sly grin on his face and the glint in Len's eyes said it all.’
      • ‘At the Chelsea Flower Show, Ann-Marie Powell finds garden designers looking to a geometric future and enjoys japesters taking a sly dig at the past’
      • ‘Was voting for these awards a sly dig at the American establishment?’
      • ‘A sly, mischievous grin then appeared on the thief's face.’
      • ‘He seems touched but then can't resist having a sly dig at himself by pointing out that the really tender thing to have done would have been not to include it on the album.’
      • ‘‘Something for you to eat,’ replies the breakfast girl with a sly grin.’
      • ‘On the cover shot, Fleck sports a sly grin as if he knew what a wonderful journey he was about to embark on.’
      • ‘Stan nodded conspiratorially, a sly grin creeping over his face.’
      • ‘He couldn't resist what appeared a sly dig at the directors of Dundee, suggesting that by refusing to accept his offer to invest, they were willing to risk their club's financial well-being.’
      • ‘He used to peel down to his jockstrap, muscles glistening, sly grin flashing, while firing cryptic answers at the media, which he loathed.’
      • ‘Juliano would turn around and there would be Petty, looking at him with a sly grin that said, ‘I got you again.’’
      • ‘His hair will be carefully dishevelled (by me), he will be unshaven, and he will wear a sly grin.’
      • ‘Galloway asked them, with a sly grin, to look out for his car.’
      • ‘His early morning frown slowly turned into a sly, cheeky grin, as if to say, ‘Look what I've found.’’
      • ‘The entire nation tuned in to watch his presentation of the 1994-1995 budget interspersed with Urdu couplets and sly digs at the opposition.’
      roguish, mischievous, impish, puckish, playful, teasing, naughty, wicked, waggish
      View synonyms
    2. 1.2 (of an action) surreptitious.
      ‘a sly sip of water’
      • ‘Nelson took a sip of the wine and a sly smile appeared.’
      surreptitious, furtive, stealthy, covert, secret
      View synonyms


Middle English (also in the sense dexterous): from Old Norse slœgr cunning originally able to strike from the verb slá; compare with sleight.