Akkadian

nabultu - cadaver (AHw. 700, CAD n1 328)

with an unexplained loss of -b-

PS
*nabī̆l-at- - corpse, carcass (SED I No. 194)

Cf. a related verb *nbl ‘to decay, die’. Cf. Sem. *npl - to fall (e. g. in [HALOT 709]) and such derived forms, probably developed by contamination with the present root, as Hbr. mappälät ‘carcass’ [HALOT 618] (< *ma-npal­-t-­), Syr. mappultā ‘cadaver’ [LSyr. 847] (< *ma-npul-t­-).