French word obscurcir comes from Old French -ir, Old French obscur

Detailed word origin of obscurcir

Dictionary entry	Language	Definition
-ir	Old French (fro)	Suffix used to form infinitives of second conjugation verbs.
obscur	Old French (fro)
obscurcir	French (fra)	(computing) to obfuscate. (figuratively) to obscure, to blur. (reflexive) to become obscure. (reflexive, of sky) to darken. To darken (a colour).

Words with the same origin as obscurcir