noun
exploit; achievement; great deed
Refers to a notable accomplishment, often of historical or lasting significance. Slightly formal and literary.
彼の功業は後世に語り継がれている。
His great achievements are passed down to future generations.
この事業は彼の最大の功業とされている。
This undertaking is considered his greatest exploit.
Compound of 功 (merit, achievement) and 業 (work, deed). The exact historical derivation is uncertain, but the combination naturally conveys the idea of a meritorious deed.