Has often been derived from *rḥb in Semitic lexicography (BDB 931, HALOT 1212 and elsewhere). In view of numerous semantic paralells throughout WS, this comparison to some extent preserves its attractivity, but is nevertheless likely to be abandoned since the morphological shape of the Akkadian word is scarcely compatible with *rḥb in the prototype.
No connection with ribītu ‘groin’ or *ˀarbaˁ- ‘four’ (Kogan 2003:131f.).