gladden (v.)youdaoicibaDictYouDict[gladden 词源字典]
c. 1300, "to be glad;" 1550s, "to make glad;" see glad (adj.) + -en (1). Earlier in both senses was simply glad (v.), from Old English gladian, Mercian gleadian "be glad; make glad." Related: Gladdened; gladdening.[gladden etymology, gladden origin, 英语词源]