'Bhugol' literally means 'Earth-ball' or Earth sphere, and refers to geography or the spherical model of the Earth used in Indian astronomy. Ancient Indian astronomers like Aryabhata, Varahamihira, and Brahmagupta all discussed the spherical nature of the Earth. Varahamihira's Brihat-Samhita includes extensive sections on geography and cosmology. While Aryabhata also used the term 'Bhugola' in Aryabhatiya, Varahamihira's broader coverage and association with summarizing various Siddhantas makes him a likely intended answer in the context of a question linking the term to the Surya Siddhanta tradition.