IPA: /ˈrɒtənəs/
KK: /ˈrɑtənnəs/
The state or quality of being decayed or decomposed, often resulting in a foul smell or appearance.
The rottenness of the fruit made it inedible.
Rottenness → It is formed from "rotten" (from Old English *rotian*, meaning to decay or decompose) and "-ness" (meaning the state or quality of). The word "rottenness" refers to the state of being rotten or decayed.
Think of something that is in a state of decay — 'rotten' describes that condition, and '-ness' indicates the quality of being in that state.