Definition sly
Etymology
From Middle English sly, sley, from Old Norse slǣgr, slœgr (“sly, cunning”, literally “capable of hitting or striking”), from Proto-Germanic *slōgiz (“lively, agile, cunning, sly, striking”), from Proto-Indo-European *slak- (“to hit, throw”). Cognate with Icelandic slægur (“crafty, sly”), Norwegian Nynorsk sløg (“sly”), Saterland Frisian slau (“sly, crafty”), Dutch sluw (“sly, cunning”), Low German slu (“sly, cunning”), German schlau (“clever, crafty”). Related to sleight, slay.
Adjective
sly (comparative slier or slyer, superlative sliest or slyest)
- Artfully cunning; secretly mischievous; wily.
- (having a positive sense) Dexterous in performing an action, so as to escape notice
- Done with, and marked by, artful and dexterous secrecy; subtle
- Light or delicate; slight; thin.
Adverb
sly
- Slyly.