Divergence, Divergency, n.
Etymology: [Cf. F. divergence.]
1. A receding from each other in moving from a common center; the state of being divergent; as, an angle is made by the divergence of straight lines. Rays come to the eye in a state of divergency.
2. Disagreement; difference. Related with some divergence by other writers. Sir G. C. Lewis.
Shades of meaning
Fernald has no entry of its own for divergence; he lists it under difference.
He lists it without comment; the entries above explain its neighbors.