largely
adverb
ˈlɑːdʒli 
ˈlɑːrdʒli to a great extent; mostly or mainly
the manager who is largely responsible for the team's victoryIt was largely a matter of trial and error.He resigned largely because of the stories in the press.
Definition of largely adverb from the Oxford Advanced Learner's Dictionary
ˈlɑːdʒli ˈlɑːrdʒli 