A pejorative or slur is a word or grammatical form expressing a negative 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.
When a term begins as pejorative and eventually is adopted in a non-pejorative sense, this is called "melioration" in historical linguistics. It may also be called amelioration, reclaiming, or semantic change. An example is queer, which was reclaimed by activists and academics starting in the early 1990s.