elderly (adj.)youdaoicibaDictYouDict[elderly 词源字典]
"bordering on old age, somewhat old," 1610s, from elder + -ly (1). Now, generally, "old." Old English ealdorlic meant "chief, princely, excellent, authentic." Old English also had related eldernliche "of old time," literally "forefatherly."[elderly etymology, elderly origin, 英语词源]