source: By alerante, based on PDF linked above - Symbols-Safety, Foundation for Promoting Personal Mobility and Ecological Transportation, abbreviated as the Eco-Mo Foundation, Public Domain

noun (plural emergencies)

a serious, unexpected, and often dangerous situation requiring immediate action:

緊急, 非常事態, 危機状態; ｟遠回しに｠ 戦争, 有事

e.g. your quick response in an emergency could be a lifesaver

e.g. times of emergency.

as modifier arising from or needed or used in an emergency:

緊急時の; 非常用の; 救急の

e.g. an emergency exit.

a person with a medical condition requiring immediate treatment.

緊急治療を必要とする状態; 急患; ｟米｠ 急患病棟.

North American short for emergency room:

｟米｠ (病院の)緊急治療室(｟略｠ ER)(｟英｠ casualty)

e.g. he was rushed into emergency.

mid 17th century: from medieval Latin emergentia, from Latin emergere ‘arise, bring to light’ (see emerge).