Akkadian

apāru - to provide with a headdress, to put a covering on someone's head (CAD A₂ 166, AHw. 57, 1544)

Also attested as ḫapāru (Kogan 2001: 279).

Also more general 'to cover, coat'(?) – for a discussion see Kogan 2001: 279.

PS
*γpr - to cover (Kogan 2001: 279)