mischievous

Adjective

Synonyms: arch impish implike pixilated prankish puckish wicked

WordNet 3.0

Adjective (2)

naughtily or annoyingly playful“teasing and worrying with impish laughter”“a wicked prank”Synonyms: arch impish implike pixilated prankish puckish wicked
deliberately causing harm or damage“mischievous rumors and falsehoods”

Webster's Dictionary (GCIDE)

Mischievous \Mis"chie*vous\ (m[i^]s"ch[-e]*v[u^]s), a. Causing mischief; harmful; hurtful; -- now often applied where the evil is done carelessly or in sport; as, a mischievous child. "Most mischievous foul sin." --Shak. [1913 Webster]

This false, wily, doubling disposition is intolerably mischievous to society. --South. [1913 Webster]

Syn: Harmful; hurtful; detrimental; noxious; pernicious; destructive. [1913 Webster] -- Mis"chie*vous*ly, adv. -- Mis"chie*vous*ness, n. [1913 Webster]