Most Sem. forms with a reduplicated second radical may be derived after various deverbal paterns from *mrr ‘to be bitter’. However, the fact that besides nominal forms meaning ‘bile, gall, gall-bladder’, there are also terms throughout Sem. meaning only ‘gall-bladder’, and even ‘bladder’ (in Gur). and ‘stomach’ (in Soq.), makes one doubt that this anatomical term derived from the verb ‘to be bitter’; a contamination with this verb (especially in case of Arm. and Hbr. pB. ‘poison’) is very likely.
Oddly enough, reflected only in Arabic and Akkadian. Despite all the difficulties, Akkadian to Arabic borrowing is not to be ruled out (Kogan–Krebernik 2021a:392).