vergency

plural vergencies

1. datedThe act of verging or approaching; tendency, inclination towards something.First known use 1668

   1721 Nathan Bailey, An Universal Etymological English Dictionary, E. Bell, London. "VERGENCY [of vergere, L.] a bending or declining away, from or to, inclining."

   2 more examples

   s.v. hanker: "vergency, incline"

   1668, John Wilkins, An Alphabetical Dictionary: Wherein All English Words According to Their Various Significations, are Either Referred to Their Places in the Philosophical Tables, Or Explained by Such Words as are in Those Tables, J.M

   the Earth is moved about the Sun by its Inclination and Vergency towards it

   1704, Plutarch's Morals, volume 3, London: Thomas Braddyll, page 155

2. The reciprocal of the focal distance of a lens, used as a measure of the divergence or convergence of a pencil of rays.

   When, by the pencil becoming oblique to the surface, the vergency produced on the pencil becomes changed, the primary and secondary focal points, V and H, separate […]

   1863, The Civil Engineer and Architect's Journal