rotten

the word "rotten" entered middle english from old norse 'rotinn', meaning decayed, which itself is the past participle of the verb 'rotna' (to rot). this norse term is cognate with the old english word 'rotian', also meaning to rot, both tracing back to a common germanic root. the core concept of decomposition has remained remarkably stable. over time, its application broadened metaphorically, allowing it to describe anything perceived as morally corrupt or of very poor quality, extending the sense of decay from the physical to the abstract.

the word is a simplex form derived from a scandinavian source. the old norse root 'rotinn' (decayed) is the direct ancestor. the '-en' ending is an old past participle suffix that became fossilized in the english word.