Proto-North Caucasian: *-r- (/-b-)
Meaning: frequentative / factitive infix (class marker?)
Notes: All highly questionable. All these morphemes may have been original (prefixed or suffixed) class markers, or else may be quite unrelated with each other. Cf. also Hurr., Urart. -ar- 'factitive (causative) suffix' - positionally closest to Avar -r-, but semantically - to PWC *r-.
