IPA: //ˈrɒtənɪst//
KK: /ˈrɑːtənɪst/
The most decayed or spoiled, often used to describe food or something that has gone bad.
The fruit in the basket was the rottenest I've ever seen, with a terrible smell.
Comparative: rotten
Superlative: rottenest
Rottenest → It is formed from "rotten" (from Old English "rotian", meaning to decay or decompose) and the superlative suffix "-est" (meaning most). The word "rottenest" means the most decayed or decomposed.
Think of something that is decaying or decomposing ('rotten') and remember that 'rottenest' describes the most decayed of all.