Pejorative

A pejorative or slur is a word or grammatical form expressing a negative or a disrespectful connotation, a low opinion, or a lack of respect toward someone or something. It is also used to express criticism, hostility, or disregard. Sometimes, a term is regarded as pejorative in some social or ethnic groups but not in others, or may be originally pejorative but later adopt a non-pejorative sense (or vice versa) in some or all contexts.
Etymology.
The word "pejorative" is derived from a Late Latin past participle stem of "peiorare", meaning "to make worse", from "peior" "worse".
Pejoration and melioration.
In historical linguistics, the process of an inoffensive word becoming pejorative is a form of semantic drift known as pejoration. An example of pejoration is the shift in meaning of the word "silly" from meaning that a person was happy and fortunate to meaning that they are foolish and unsophisticated. The process of pejoration can repeat itself around a single concept, leaping from word to word in a phenomenon known as the euphemism treadmill, for example as in the successive pejoration of the terms "bog-house", "privy-house", "latrine", "water closet", "toilet", "bathroom" and "restroom".
When a term begins as pejorative and eventually is adopted in a non-pejorative sense, this is called melioration or amelioration. One example is the shift in meaning of the word "nice" from meaning a person was foolish to meaning that a person is pleasant. When performed deliberately, it is described as reclamation or reappropriation. An example of a reclaimed word is queer, which was re-appropriated as a positive term by activists and academics starting in the early 1990s.