羽う弁べんうべんMeanings1nounvane; web (of a feather)ornithologyOrnithological term for the flat part of a feather, consisting of barbs extending from the rachis.鳥とりの羽う弁べんは、羽う軸じくから伸のびる枝えだによって形けい成せいされる。The vane of a bird's feather is formed by barbs extending from the rachis.