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.
他们已经偷偷约会了好几个月。
Examples from the Corpus
on the sly• Dick had started drinking again on the sly.• He certainly wasn't dumping his pints on the flooron 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 dresson the sly and Halle hung his hitchingrope 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 smartestgirl passes answerson the sly to her table-mates.• We try and slip him in on the sly when we think we've got them hooked.