Syriac

garmīdā, gurmīdā - cubitus, ulna (LSyr. 133)

PS
*kVm(V)d- - forearm, cubit (SED I No. 144)
A phonetic diversity throughout Sem. can be explained by (1) lower compatibility of a voiced and voiceless stop in Hbr. and Arm., and (2) change of *­m­ > ­n­ in contact with ­-d (for a similar phonetic evolution cf. *p/ban/md(­at)­ ‘back, podex’, No. 216).