All 3 Uses of

inconsistent
in
Northanger Abbey

To Catherine's simple feelings, this odd sort of reserve seemed neither kindly meant, nor consistently supported; and its unkindness she would hardly have forborne pointing out, had its inconsistency been less their friend; but Anne and Maria soon set her heart at ease by the sagacity of their "I know what"; and the evening was spent in a sort of war of wit, a display of family ingenuity, on one side in the mystery of an affected secret, on the other of undefined discovery, all equally acute.†
Chpt 15

To pass between lodges of a modern appearance, to find herself with such ease in the very precincts of the abbey, and driven so rapidly along a smooth, level road of fine gravel, without obstacle, alarm, or solemnity of any kind, struck her as odd and inconsistent.†
Chpt 20

Its inconsistencies, contradictions, and falsehood struck her from the very first.†
Chpt 27 *

Definition:

not the same in different parts or at different times

or:

not in agreement [with something else]