Akkadian

gappu - wing (CAD K 185, AHw. 281)

Var. agappu.
Identified by CAD with kappu, but treated as a separate entry in AHw, which seems right in view of the comparative data; note that in AHw agappu is also treated as a separate gloss independent of gappu (AHw 15).

PS
*gapp-, *ˀa-gapp- - wing (SED I No. 88)
There is a trend to compare this root with Sem. *gd/ḏp ‘to fly’ > *gadp- ‘wing’ implying a secondary formation with loss of *-d-, which is unlikely