I. adjective
1.
Synonyms: clever 4, adroit, canny, ||coony, cunning, dexterous, ingenious, ||sleighty, slim
Related Word: smart; cagey; masterful
2.
attaining or seeking to attain one's ends by devious means
a sly way of upping sales
Synonyms: artful, astute, crafty, cunning, deep, ||downy, foxy, guileful, insidious, subdolous, subtle, tricky, vulpine, wily; compare underhand
Related Word: disingenuous, unfrank; calculating, designing, Machiavellian, scheming; cagey, devious, shady, shifty, ||slanter, slick, slippery, smooth; clandestine, covert, furtive, stealthy; underhand, underhanded, unscrupulous; predatory; crooked, dishonest
Idioms: crazy like a fox, cunning as a fox ( or serpent), sly as a fox
Contrasted words: candid, forthright, frank, honest, open, sincere, straightforward
II. verb
Synonyms: sneak , creep, gumshoe, lurk, skulk, slide, slink, ||snake, ||snook, steal