[1] : The Collaborative International Dictionary of English v.0.48

mischievous \mis"chievous\ mi^s"ch-evu^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"chievously, adv. --
        mis"chievousness, n.
        1913 webster
see also:
mis"chievously mis"chievousness 

[2] : WordNet (r) 2.0

mischievously
     adv : in a disobedient or naughty way; "he behaved badly in
           school"; "he mischievously looked for a chance to
           embarrass his sister"; "behaved naughtily when they had
           guests and was sent to his room" syn: badly, naughtily
see also:
badly naughtily 

Mischievously >> M Words
Mischievously, definition of term: Mischievously
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