ambulance vs emergency

ambulance

noun
  • A mobile field hospital. 

  • An emergency vehicle designed for transporting seriously ill or injured people to a hospital. 

verb
  • To transport by ambulance. 

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. 

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