*γdr - to be obscure, black (Kogan 2001: 280)

Akkadian

adāru - to become obscured (of heavenly bodies), to become eclipsed; to be worried, disturbed, restless (CAD A₁ 103, AHw 11)

Also attested as ḫadāru (Kogan 2001: 279-280).

Arabic

γdr - to act perfidiously, to break a compact; to remain, to lag behind; to be(come) dark (of the night) (Lane 2231-2232)