You searched for: “amelioration
1. To make or to become better; to improve.
2. Changes that take place in languages so word meanings are more acceptable or so they have more respectable meanings. Synonym: melioration.
amelioration, melioration, pejoration
amelioration (uh meel" yuh RAY shuhn) (noun)
A making or becoming better; improvement: Efforts of amelioration are being made for the suffering of people who have lost their jobs.
melioration (meel" yuh RAY shuhn; mee" lee uh RAY shuhn) (noun)
1. The act or process of improving something or the state of being improved: The workers are hoping for a melioration of the financial situation for their company.
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".
pejoration (pej uh RAY shuhn; pee" juh RAY shuhn) (noun)
1. The process or condition of worsening or degenerating; deterioration: The global financial situation is going through a process of pejoration.
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.