Akkadian

niālu - to lie down (CAD N₁ 204, AHw. 784)

Cf. itūlu ‘to lie down, to sleep’ (CAD U/W 344), Gt of niālu (Huehnergard 2002a:178-184).
Derived from *layliy- with dissimilation (Kogan 2015: 297 n. 844).

PS
*layliy(-at)- - night (CDG 314, Fronzaroli 1965a: 141, 147, 150; Kogan 2011: 196; Kogan 2015: 33)