Akkadian

ḫaḫḫu - plum tree; peach tree (CAD Ḫ 29, AHw. 308, CDA 101)

See most recently Kogan 2012a:254f.

PWS
*ḫāḫ- - plum tree (Fronzaroli 1969: 7, 25, 33)
The form should be probably postulated for PWS level, since there are chances that Akkadian ḫaḫḫu is a West Semitic loanword, s. Kogan 2012: 255