*coherency*

{ , n. [ L. cohaerentia: cf. F. cohérence. ] 1. A sticking or cleaving together; union of parts of the same body; cohesion. [ 1913 Webster ]

2. Connection or dependence, proceeding from the subordination of the parts of a thing to one principle or purpose, as in the parts of a discourse, or of a system of philosophy; a logical and orderly and consistent relation of parts; consecutiveness. [ 1913 Webster ]

Coherence of discourse, and a direct tendency of all the parts of it to the argument in hand, are most eminently to be found in him. Locke. [ 1913 Webster ]

3. the state of cohering.
Syn. -- cohesion, cohesiveness. [ WordNet 1.5 ]