melioration

名词 melioration:

1. the act of relieving ills and changing for the better
   同义词：amelioration, betterment
2. a condition superior to an earlier condition
   同义词：improvement
3. the linguistic process in which over a period of time a word grows more positive in connotation or more elevated in meaning

mel.io.ra.tion

n.（名词）

The act or process of improving something or the state of being improved.
改善：改进某物的行动或过程或正在被改进的状态
An improvement.
改进
The linguistic process by which a word over a period of time grows more elevated in meaning or more positive in connotation.
改良：在一段时期里一个字的语义逐渐提高及内涵更明确的语言学过程