abbreviation of emergency room, by 1965.
er
as a sound of hesitation or uncertainty, attested from mid-19c.
updated on August 16, 2010
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。