Coherence \Co*her"ence\, Coherency \Co*her"en*cy\, n. [L. cohaerentia: cf. F. coh['e]rence.]

1. A sticking or cleaving together; union of parts of the same body; cohesion.

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; consecutiveness.

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.

Source: Webster's Revised Unabridged Dictionary (1913)