Arabic

ǯff - agiter les ailes (se dit d'un oiseau qui couve) (to wave wings (said of a brooding bird) (BK 1 302)

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