The Collaborative International Dictionary of English v.0.48:

Maleficent \Ma*lef"i*cent\, a. [See Malefic.]
   Doing evil to others; harmful; mischievous.
   [1913 Webster]

WordNet (r) 3.0 (2006):

maleficent
    adj 1: harmful or evil in intent or effect [ant: beneficent]