An Etymological Dictionary of the German Language/Fahne
Fahne, f. (mas. in UpG.), ‘banner, flag, standard, squadron,’ from MidHG. vane, van, m. ‘flag, banner’; in this sense OHG. has the compound gundfano, m., since fano most frequently means ‘cloth’ (comp. ougafano, ‘veil,’ halsfano, ‘neckcloth’); allied to Goth. fana, ‘cloth, stuff, rag,’ AS. fana and gûþfana, m., ‘standard, banner,’ E. fane, vane, Du. vaan, ‘flag.’ The Teut. fanan, pre-Teut. pano-n-, has in the wider sphere of the Aryan languages many cognates which also point to the general and older meaning, ‘stuff, cloth’; Lat. pannus, ‘small piece of cloth, rag,’ OSlov. o-pona, ‘curtain,’ ponjava, f., ‘sail.’ Akin also perhaps to Gr. πῆνος, n., ‘garment,’ πηνίον, ‘spool, spindle.’ An Aryan verbal root, pen, appears in OSlov. pĭną (pęti), ‘to span, hang.’ The OTeut. gunþfano, ‘standard,’ was adopted with the meaning ‘flag’ by Romance (comp. Fr. gonfalon, Ital. gonfalone), while the simple form in Romance retained at different times the earlier and general meaning (comp. OFr. and ModFr. fanon, ‘rag, towel, fanon (of a priest).’ —