emergency vs emergency department

emergency

noun
  • The department of a hospital that treats emergencies. 

  • Arising from or used in an emergency. 

  • A situation which poses an immediate risk and which requires urgent attention. 

  • An individual brought in at short notice to replace a member of staff, a player in a sporting team, etc. 

emergency department

noun
  • A department of a hospital where seriously ill or injured patients, often with life-threatening conditions that require urgent or immediate treatment, are brought in, usually by ambulance. 

How often have the words emergency and emergency department occurred in a corpus of books? (source: Google Ngram Viewer )