Sly
/slaɪ/
adjective
Artfully cunning; secretly mischievous; wily.
(having a positive sense) Dexterous in performing an action, so as to escape notice
Done with, and marked by, artful and dexterous secrecy; subtle
“a sly trick”
Synonyms: artful, cautious, nimble, shrewd, skillful, crafty, cunning, knowing
adverb
Slyly.