11 letters · 21 points in Scrabble
adjective naughtily or annoyingly playful
adjective deliberately causing harm or damage
originFrom Middle English myschevous, mischevous, from Anglo-Norman meschevous, from Old French meschever, from mes- (“mis-”) + chever (“come to an end”) (from chef (“head”)). By surface analysis, mischief + -ous.
Etymology from Wiktionary, CC BY-SA 3.0