From Middle English feþer, from Old English feþer, from Proto-West Germanic *feþru, from Proto-Germanic *feþrō (compare West Frisian fear, German Low German Fedder, Dutch veder, veer, German Feder, Yiddish פֿעדער (feder), Danish fjer, Swedish fjäder, Norwegian Bokmål fjær, fjør, Norwegian Nynorsk fjør), from Proto-Indo-European *péth₂r̥ (“feather, wing”), from *peth₂- (“to fly”). Cognate with Ancient Greek πέτομαι (pétomai), Albanian shpend (“bird”), Latin penna, Old Armenian թիռ (tʿiṙ).
An airplane wing with two propellers, of which the one on the right has been feathered
feather (third-person singular simple present feathers, present participle feathering, simple past and past participle feathered)
aeronautics: to streamline an aircraft's propeller blades when shut downThe translations below need to be checked and inserted above into the appropriate translation tables, removing any numbers. Numbers do not necessarily match those in definitions. See instructions at Wiktionary:Entry layout § Translations.