- (architecture) An onion-shaped dome, characteristic of august buildings in Moghul and Russian architecture
1993, Leland M. Roth, Understanding Architecture: Its Elements, History, and Meaning, page 523:
- an onion dome may have a shape that is somewhat more than a half sphere and may be pointed at the top
2001, Carol Strickland, Amy Handy, Patty Brown, The Annotated Arch: A Crash Course in the History of Architecture, page 36:
- The characteristic bulging onion dome, which is a signature of Russian [church] architecture, came into being to shed heavy snow.