Translation guide
A cupola is a small dome-like structure on top of a building, often used for light, ventilation, or decoration. In Japanese, it is usually described rather than translated with a single common word.
The learner wants to refer to a small dome or turret on a roof, often with windows.
Loanword from English, understood in architectural contexts. Most direct equivalent.
That building has a cupola on its roof.
Literally 'small dome'. Used when the cupola is dome-shaped.
There is a small dome on top of the roof.
Descriptive phrase meaning 'small tower on the roof'. Used when the cupola is more tower-like.
The small tower on the church roof is beautiful.
The learner is talking about a cylindrical furnace used in metal casting, often called a cupola furnace.
The English word 'cupola' is relatively specialized. In Japanese, キューポラ is a direct loanword but may not be widely known outside architectural or industrial fields. For general conversation, describing the structure (e.g., 屋根の上の丸い部分) is often clearer.