noun, noun or participle which takes 'suru', intransitive verb
ruin; downfall; collapse; bankruptcy
Refers to the decline or fall of a family, business, or social standing, often from prosperity to ruin. Used both as a noun and with する to describe the process.
その名家は一代で没落した。
That distinguished family fell into ruin in a single generation.
事業の失敗で彼は没落の道をたどった。
After his business failed, he went down the path to ruin.