sneaky /ˈsniːki/adjective 2noun 1forms 3phrases 1 adjective2 •Dishonest; deceitful.They played a sneaky trick on us. •Elusive; difficult to capture or observe due to constantly outwitting the adversaries.Catching those thieves will be hard: they're so sneaky! noun1 •(slang) Any device used for covert surveillance.[…] in cooperation with the National Security Agency, installs and maintains "sneakies" throughout the U.S.S.R. and Communist China — but increasingly, denied areas are surveyed more simply. — 1974 formssneakies · sneakier · sneakiest Phrases with sneaky sneaky PeteA sneaky person.