noun
greatly senior person; veteran
Refers to someone far more senior in age, experience, or rank, often in a workplace, school, or organization. Carries strong respect.
彼は私よりずっと大先輩で、入社して三十年になる。
He is a much more senior colleague than I am, having joined the company thirty years ago.
I can't help but get nervous in front of such a senior person.