I. ˈrask(ə)lē, ˈraas-, -li, chiefly Brit ˈrȧs- adjective
Etymology: rascal (I) + -ly
1. obsolete : of or relating to the rabble
2. : of or characteristic of a rascal : meanly tricky or dishonest : mean , base , worthless
notorious for their quarrelsome and rascally proclivities — Jack London
our rascally porter is fallen fast asleep — Jonathan Swift
II. adverb
: in a rascally fashion