"life at ease," by 1902 (as Reilly), popularized in U.S. during World War I; it seems to have been military slang initially, sometimes said to trace to various songs but none of that title has been found.
updated on August 28, 2021
英语词源词典收录了45867条英语词源词条，基本涵盖了全部常用英语词汇的起源、历史，是研究英语词汇或通过词源学英语的必备工具。