Akkadian
ḫillu - egg membrane
(CAD ḫ 186, AHw 345)
Though this term is attested in LL only and its exact meaning is not quite clear, its co-occurence with such terms as ipu ‘membrane, afterbirth’ [CAD i 173] and ibaḫu ‘womb, uterine membrane’ [ibid. i 1] makes the comparison
with the Arb. word plausible enough.