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eaves
narrow aisle surrounding the core of a temple building
「宇」 has another reading with different meanings.
宇の下で雨宿りした。
I took shelter under the eaves.
この寺の宇は江戸時代に造られたものだ。
The eaves of this temple were built in the Edo period.
古い家の宇には燕が巣を作っている。
Swallows have built nests under the eaves of the old house.