2. Changes that take place in languages so word meanings are more acceptable or so they have more respectable meanings. Synonym: melioration.
2. The linguistic process by which a word over a period of time grows more elevated in meaning or more positive in connotation: The word "nice" has gone through the process of melioration because it formerly meant "foolish".
2. The process by which the meaning of a word becomes negative or less elevated over a period of time: The word "silly", which formerly meant "deserving sympathy, helpless, or simple", has gone through pejoration, resulting in the meanings of "showing a lack of good sense, frivolous".
Some would say that the process of the melioration of English vocabulary is balanced with the process of pejoration, because words become more elevated in meaning; while other words become less so; however, the amelioration of the situation is helped by the use of new dictionaries.