Synonyms of sly in English:

sly


See definition of sly

adjective

1‘she's getting sly in her old age’

SYNONYMS
cunning, crafty, clever, wily, artful, guileful, tricky, conniving, scheming, devious, designing, deceitful, duplicitous, dishonest, disingenuous, underhand, sneaky, untrustworthy
manipulative, calculating, Machiavellian
informal foxy, shifty
British informal fly
Australian, New Zealand informal shonky
South African informal slim
archaic subtle
rare carny
ANTONYMS

honest, artless

2‘he gave her a sly grin’

SYNONYMS
roguish, mischievous, impish, puckish, playful, teasing, naughty, wicked, waggish
arch, knowing
Scottish, Northern English informal pawky

3‘she took a sly sip of water’

SYNONYMS
surreptitious, furtive, stealthy, covert, secret