Source : Webster's Revised Unabridged Dictionary (1913)

Prejudicial \Prej`u*di"cial\, a. [L. praejudicialis belonging to
   a preceding judgment: cf. F. pr['e]judiciel.]
   1. Biased, possessed, or blinded by prejudices; as, to look
      with a prejudicial eye. [Obs.] --Holyday.

   2. Tending to obstruct or impair; hurtful; injurious;
      disadvantageous; detrimental. --Hooker.

            His going away . . . was most prejudicial and most
            ruinous to the king's affairs.        --Clarendon.
      -- {Prej`u*di"cial*ly}, adv. -- {Prej`u*di"cial*ness}, n.

Source : WordNet®

prejudicial
     adj : (sometimes followed by `to') causing harm or injury;
           "damaging to career and reputation"; "the reporter's
           coverage resulted in prejudicial publicity for the
           defendant" [syn: {damaging}, {detrimental}, {prejudicious}]