Etymograph

English

inactinic

From in- + actinic.

Formed from in- + actinic

Proto-Indo-European *h₁én ‘in’

Proto-Germanic *in ‘into’

English in-

Ancient Greek ἀκτίς ‘ray’

English actinic

Today it means

adj That does not produce photochemical reactions (and can be used as a safelight in a photographic darkroom) (of light)

Language periods are conventional ranges, not dates for this word.

Etymograph / inactinic