sly

 
Pronunciation: /slʌɪ/

adjective (slyer, slyest)

  • having or showing a cunning and deceitful nature: a sly, manipulative woman
  • showing in an insinuating way that one has some secret knowledge that may be harmful or embarrassing: he gave a sly grin
  • (of an action) surreptitious: a sly sip of water

Phrases

on the sly

in a secretive fashion: she was drinking on the sly

Derivatives

slyly

(also slily) adverb

slyness

noun

Origin:

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