noun
glorious achievement; great undertaking
A formal, literary term for a magnificent accomplishment or grand enterprise. Rarely used in everyday conversation; found mainly in historical or elevated writing.
彼の生涯はまさに鴻業と呼ぶにふさわしい。
His life's work is truly worthy of being called a glorious achievement.
Compound of 鴻 (large, grand) and 業 (achievement, work). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning 'glorious achievement'.