Arabic

ˀaḫmaṣ- - middle of the body, slim mid body (BK 1 633)

Cf. ḫmṣ ‘to be empty (said of the belly); de-swelling (said of a wound from which the swelling goes away)’ [ibid.] (cf. the latter meaning also in ḫmṣ [ibid. 492])

PS
*ḫam/nṣ- - waist (SED I No. 132)
Scarcely attested (in Akk. and Arb.); phonetically and semantically highly problematic. Vocalism based on Akk. only, as the Arb. form represents a derived pattern.