rose window
Architectural term for a circular stained-glass window with radiating petal-like sections, typical of Gothic cathedrals.
The rose window of Notre-Dame Cathedral is very famous.
Full kanji spelling; 薔薇 is a common kanji for 'rose' but may be less familiar to some readers.
Compound of バラ (rose) and 窓 (window), a direct calque of English 'rose window'.