洋葱形屋顶(多见于俄罗斯教堂)

[ noun ]
a dome that is shaped like a bulb; characteristic of Russian and Byzantine church architecture
<noun.artifact>

onion dome \on`ion dome"\, n. (Architecture)
A dome with a pointed top, its width often extending beyond
the width of the tower it covers; -- a style of architecture
characteristic of Russian Orthodox churches.
[PJC]