viridian (adj.)

late 14c., "fresh green color," from Old French verdure "greenness, greenery, green fields, herbs," from verd, variant of vert "green" (12c.), from Latin viridis "green" (source of Spanish, Italian verde), related to virere "be green," virescere "turn green," viridare "be green," all of which are of uncertain etymology. De Vaan writes, "None of the adduced set of cognates (Lat. 'green', Baltic 'multiply, fruit', Gm. 'sprout, meadow') undoubtedly belong together." The meaning "green plants, vegetation" is attested from c. 1400.

variant of suffix -an (q.v.), with connective -i-. From Latin -ianus, in which the -i- originally was from the stem of the word being attached but later came to be felt as connective. In Middle English frequently it was -ien, via French.