sly /slaɪ/ adjectiveadj 1. INTELLIGENTsomeone who is sly cleverly deceives people in order to get what they want 狡猾的，狡诈的 SYN cunning► see thesaurus at dishonest 2 sly smile/glance/wink etc SECRETa smile, look etc that shows you know something secret 诡秘的微笑/一瞥/眨眼等 He leaned forward with a sly smile.
sly smile/glance/wink etc• All those gloating women looking down into his grave, whispering their sisterly secrets behind their sly smiles.• He was relieved when he saw Earnhardt's trademark sly smile.• Magrat took her seat and, to Agnes's amazement, gave her a sly wink.• Mitchell was shocked to see the man signaling him with sly winks.• Wickham saw Marshall's sly smile and understood what he was thinking.• Herbie's face had also lit in a sly smile as Mary had passed.• By his sly smile, I think this is the one he intended. 3 on the sly informalSECRET secretly, especially when you are doing something that you should not do 秘密地，偷偷地，暗地里 They’d been seeing each other on the sly for months.
on the sly• Dick had started drinking again on the sly.• He certainly wasn't dumping his pints on the floor on the sly.• I won't be party to your bitching yourself on the sly.• So we continued to meet on the sly.• Elmer Gantry feels guilty for his vices: seeing people on the sly and drinking.• Sethe made a dress on the sly and Halle hung his hitching rope from a nail on the wall of her cabin.• Sometimes she would give him money on the sly and he would help her with chores.• The smartest girl passes answers on the sly to her table-mates.• We try and slip him in on the sly when we think we've got them hooked.
—slyness noun [uncountableU]