rotter

The word "rotter" is a vivid example of English's capacity for moral metaphor, built upon the native Germanic root "rot." The core concept of physical decay and putrefaction, inherited from Proto-Germanic rutōną, was extended metaphorically to describe corrupt or worthless character. By appending the agent-forming suffix "-er," common in Old English, the abstract quality of decay was personified into a noun for a contemptible individual. This pejorative slang term, emerging in the late 19th century, encapsulates the logic of equating moral deficiency with organic decomposition.

Structure: rot (decay) + er (agent suffix) - rot: From Middle English 'rotten', of Germanic origin; related to Old Norse 'rotna' (to decay). In this word, it functions as the core root conveying the sense of moral or personal decay. - er: A native English suffix of Germanic origin, used to form agent nouns indicating a person or thing that performs the action of the verb (e.g., writer, baker). Here, it denotes "one who is characterized by rot/decay."