From Longman Dictionary of Contemporary Englishlargelylarge‧ly /ˈlɑːdʒli $ ˈlɑːr-/ ●●○ W2 adverb MOSTmostly or mainly The state of Nevada is largely desert. It had been a tiring day, largely because of all the tedious waiting.
Examples from the Corpus
largely• Our church's congregation is largely made up of young families with children.• Most of the cities depend largely on hydroelectric power. 