freshen (v.)youdaoicibaDictYouDict[freshen 词源字典]
1690s, "grow brisk, grow stronger" (intransitive), from fresh (adj.1) + -en (1). The earlier verb was simply fresh (mid-14c.). Transitive sense "refresh, revive, renew" is from 1749. Of a drink, "to top off," from 1961. Related: Freshened; freshening.[freshen etymology, freshen origin, 英语词源]