emergency
n.
"unforeseen occurrence requiring immediate attention," 1630s, from Latin emergens, present participle of emergere "to rise out or up" (see emerge). Or from emerge + -ency. As an adjective by 1881.
〔蒋〕[merg=dip，sink沉，没(merg也作mers)，-ency名词后缀] 突然出现的情况;突然事件，意外之变;紧急情况