Possibly a corruption of medo 目処. A gap between two things. A board used to cover or fill a gap is called mendo-ita 面戸板. Where there are gaps on a tiled roof, filler tiles called *mendogawara 面戸瓦 are used to close them. Mendo is also a board that fills a gap between a rafter *taruki 垂木, and the eave purlin *gagyō 丸桁. Other gaps include: nokisaki mendo 軒先面戸, the gap between the visible eaves filler *uragō 裏甲, and eave end tiles *gatō 瓦当; kirimendo 切面戸, the gaps between rafters; and when such gaps are filled by being placed over the rafters they are called tōshimendo 通し面戸. Notching, kaku 欠く, on rafters for inserting filler boards is called mendogiri 面戸切. Filler tiles are *tanimendo 谷面戸, and filler tiles placed between broad concave tiles on the ridge *tsuijimendo 築地面戸.