From Longman Dictionary of Contemporary Englishslysly /slaɪ/ adjective 1 INTELLIGENTsomeone who is sly cleverly deceives people in order to get what they want SYN cunning► see thesaurus at dishonest2 → sly smile/glance/wink etc3 → on the sly —slyly adverb —slyness noun [uncountable]
Examples from the Corpus
sly• I won't be party to your bitching yourself on the sly.• Children of that age can be very sly.• My parents didn't approve, but we continued to meet on the sly.• Eliot looked sly and deceitful, as though he wasn't telling us the whole truth.• I began to dislike her; she looked sly and I felt indignant that she'd spoken to me like that.• He wanted to forget that she was sly and spiteful and malicious.• Manshin Anjima gave me a sly look and wrote down the name of her cemetery.• A sly look crossed his face when Patsy mentioned the money.• The sly old Congressman knows what it takes to get elected.• He's a sly old devil isn't he! Nobody knew he had as much money as that!• How the sly one squeaked, howled, sizzled, hissed, and swelled his hairy carapace!• Mitchell was shocked to see the man signaling him with sly winks.Origin sly (1200-1300) Old Norse slgr 