*sly/slaɪ; slaɪ/ adj slyeror slier, slyestor sliest 1 using tricks and dishonest methods to get what you want 狡猾的，狡诈的: He's sly and greedy. 他为人狡诈贪婪。 2 showing that you know something that others do not know 诡秘的: a sly smile 诡秘的一笑 3 on the slyinformal secretly doing something you are not supposed to be doing 【非正式】 秘密地，偷偷地: He's been smoking on the sly. 他一直在偷偷地抽烟。