Source : Webster's Revised Unabridged Dictionary (1913)

Inadvertent \In`ad*vert"ent\, a. [Cf. F. inadvertant. See 2d
   {In-}, and {Advert}.]
   Not turning the mind to a matter; heedless; careless;
   negligent; inattentive.

         An inadvertent step may crush the snail That crawls at
         evening in the public path.              --Cowper.
   -- {In`ad*vert"ent*ly}, adv.

Source : WordNet®

inadvertently
     adv : without knowledge or intention; "he unwittingly deleted the
           references" [syn: {unwittingly}, {unknowingly}] [ant: {mindfully},
            {wittingly}, {wittingly}]