Syriac

mertā - gall, bile (LSyr. 400, SL 839)

PS
*mVr(V)r-at- - gall, gall bladder (SED I No. 188; Kogan 2011: 219)

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.