improvement (n.)youdaoicibaDictYouDict[improvement 词源字典]
mid-15c., enprowment "management of something for profit," from Anglo-French emprowement, from emprouwer "turn to profit" (see improve). Meaning "betterment; amelioration" is from 1640s. Meaning "buildings, etc. on a piece of property" is from 1773. Related: Improvements.[improvement etymology, improvement origin, 英语词源]