also: いちだいぶげん
noun
new money; nouveau riche; self-made wealthy person
Refers to a person who became wealthy within their own lifetime, often contrasted with inherited wealth. Can carry a slightly dismissive or envious tone.
彼は一代分限で、若い頃から事業を起こして成功した。
He is a self-made wealthy person who started a business from a young age and succeeded.
あの豪邸の主は一代分限らしい。
The owner of that mansion seems to be nouveau riche.