Faonia
From Simon Online
Faonia arabice peonia .f. pro .p. ponentes et cetera.
Translation:
Faonia is the Arabic word for Latin peonia {"peony"}. The Arabs use the sound 'f' instead of 'p', etc.
Commentary:
Cf. Siggel p.55: ﻓﺎﻭﺍﻧﻳﺎ fāwāniyā Paeonia officinalis (Ranunculac.), Pfingstrose, παιονία {sic!} {i.e. "peony"}.
Obviously the Arabic word is loaned from Greek παιωνία /paiōnía/. Simon explains that since Arabic has no 'p' sound it uses its nearest equivalent in its sound system, which is 'f'. However, it should also be mentioned that quite often Arabic 'b' replaces foreign 'p'.