Source : Webster's Revised Unabridged Dictionary (1913)

Inconsistent \In`con*sist"ent\, a. [Pref. in- not + consistent:
   cf. F. inconsistant.]
   1. Not consistent; showing inconsistency; irreconcilable;
      discordant; at variance, esp. as regards character,
      sentiment, or action; incompatible; incongruous;
      contradictory.

Source : WordNet®

inconsistent
     adj 1: displaying a lack of consistency; "inconsistent statements";
            "inconsistent with the roadmap" [ant: {consistent}]
     2: not capable of being made consistent or harmonious;
        "inconsistent accounts"
     3: not in agreement [syn: {discrepant}]