by far; far and away; outstandingly
Used to emphasize that something is markedly superior or different from others in a group. Often modifies adjectives or verbs.
He is by far the tallest in the class.
The ramen at this shop is far and away the most delicious.
From the verb 飛び抜ける (とびぬける, 'to be outstanding'), itself a compound of 飛ぶ (とぶ, 'to fly') and 抜ける (ぬける, 'to come out, to be omitted'). The adverbial form 飛抜けて is used to mean 'by far'.