everlastingyoudaoicibaDictYouDict[everlasting 词源字典]
early 13c., "eternal" (adj.); "eternally" (adv.); "eternity" (n.); from ever + lasting. Colloquially in mid-19c. U.S., "very, exceedingly." A verb, everlast, "to endure forever," is recorded late 14c. Related: Everlastingly.[everlasting etymology, everlasting origin, 英语词源]