Elusive; difficult to capture or observe due to constantly outwitting the adversaries.
Catching those thieves will be hard: they're so sneaky!
Be sneaky. Fish frighten easily.1995 April 23, Jeff Csatari, “Tackle Tips”, in Boys' Life, volume 85, number 4, Irving, Texas: Boy Scouts of America, Inc., →ISSN, page 42:
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Some fans may have mistaken the album’s floatiness for aimlessness, but Mr. Mercer’s songs have never been sneakier, or prettier.2007 October 25, Kelefa Sanneh, “Songs With a Sneaky Streak”, in The New York Times:
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Dishonest; deceitful.
They played a sneaky trick on us.
A contribution to a wall newspaper of which I was an editor in our sector poked fun at the never-changing menu in the school cafeteria. It centred on the various and devious methods used in serving us hamburger. One time it would be called hamburger, another time bifshtek, then cutlet, and sneakiest of all, schnitzel—the only difference among them was usually only in their shape or whether bread crumbs had been used.1988, Peter Hunter, “Back to School: Dealing with Dissent”, in Which Side Are You On, Boys: Canadian Life on the Left, Toronto, Ont.: Lugus Productions Ltd., →ISBN, page 96:
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Irish car bombs were a sneaky drink—they tasted like a chocolate milk shake, and more than once he'd been seduced into drinking several of them. It was only after he stood up that he realized how much of a wallop they packed.2013, Lara Lacombe, Deadly Contact, page 12:
[…] 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, Miles Copeland, Without cloak or dagger: the truth about the new espionage, page 244:
[…] has used travellers to plant 'sneakies' - small electronic transmitting devices which form part of a surveillance network.1991, Chapman Pincher, The Truth about Dirty Tricks: