Inconsistent
Inconsistent , adjective
[Prefix in- not + consistent: compare French inconsistant.]
1.
Not consistent; showing inconsistency; irreconcilable; contradictory, or having contradictory implications; discordant; at variance, esp. as regards character, sentiment, or action; incompatible; incongruous.
Compositions of this nature... show that wisdom and virtue are far from being inconsistent with politeness and good humor.
2.
Not exhibiting uniformity of sentiment, steadiness to principle, etc.; unequal; fickle; changeable.
Ah, how unjust to nature, and himself,
Is thoughtless, thankless, inconsistent man.