Old High German word -ar comes from Proto-Indo-European *-rós (Forms adjectives from |wikipedia:Caland system| roots.)
You can also see our other etymologies for the Old High German word -ar.
|*-rós||Proto-Indo-European (ine-pro)||Forms adjectives from |wikipedia:Caland system| roots.|
|*-raz||Proto-Germanic (gem-pro)||Forms adjectives from verbal roots, which usually appear in the zero-grade.|
|-ar||Old High German (goh)|