Source : Webster's Revised Unabridged Dictionary (1913)

Incongruent \In*con"gru*ent\, a. [L. incongruens. See {In-} not,
   and {Congruent}.]
   Incongruous. --Sir T. Elyot.

Source : WordNet®

incongruent
     adj : not congruent [ant: {congruent}]