Akkadian

ḫanṣātu - part of human body, possibly waist (CAD ḫ 81, AHw 321)

(pl. t.), Possibly < *ḫamṣātu (on n < m before sibilants in Akk. see [GAG 40]).

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.