also ECHO virus, 1955, acronym for enteric cytopathogenic human orphan; "orphan" because when discovered they were not known to cause any disease.
updated on September 03, 2012
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。