inconsistent

adj. incompatible, contradictory, incongruous; changeable

Consistency can refer to:Consistency proof, in mathematics, logic, and theoretical physicsConsistency (statistics), a property of estimators and estimationConsistency criterion for voting systems, which requires that whenever option A is the winner both in two districts independently it must also be the winner in the combined districtConsistency model, in computer scienceEquiconsistency in mathematics
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Adjective
1. displaying a lack of consistency; "inconsistent statements"; "inconsistent with the roadmap"
(antonym) consistent
(similar) at odds(p), conflicting, contradictory, self-contradictory
(see-also) variable
2. not capable of being made consistent or harmonious; "inconsistent accounts"
(similar) irreconcilable, unreconcilable
3. not in agreement
(synonym) discrepant
(similar) incongruous

adj. inconsistent, incompatible, contradictory, incongruous; changeable

(a.)
Not exhibiting uniformity of sentiment, steadiness to principle, etc.; unequal; fickle; changeable.
  

(a.)
Not consistent; showing inconsistency; irreconcilable; discordant; at variance, esp. as regards character, sentiment, or action; incompatible; incongruous; contradictory.