"rascally" in the adjective sense
1. devilish, rascally, roguish
playful in an appealingly bold way
"a roguish grin"
2. rascally, roguish, scoundrelly, blackguardly
lacking principles or scruples
"the rascally rabble"
"the tyranny of a scoundrelly aristocracy" - W.M. Thackaray
"the captain was set adrift by his roguish crew"
Source: WordNet® (An amazing lexical database of English)
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