An Etymological Dictionary of Astronomy and Astrophysics

Suffix used to form nouns either from adjectives or from verbs; it
expresses 1) state or condition (brilliance, absorptance); 2) action (e.g. continuance).

Etymology (EN): M.E., from O.Fr., from L. -antia.

Etymology (PE): -Egi, -igi, -âi, -âyi, -eš Pers. noun suffixes denoting state, condition.