Harsusi

ḏerā - arm (HL 29)

PWS
*ḏirāˁ- - arm, elbow (SED I 65, Kogan 2011: 224)
The traditional derivation from *ḏrˁ ‘to sow’ (Fronzaroli 1964:34, 48 and 1969:9) is difficult to prove