From Longman Dictionary of Contemporary Englishambulanceam‧bu‧lance /ˈæmbjələns/ ●●○ S3 noun [countable] 
MHTTCa special vehicle that is used to take people who are ill or injured to hospital the ambulance serviceambulance staff/crew/worker The ambulance crew removed him from the wreckage. the ambulance driverby ambulance Mike had to be taken by ambulance to hospital. Do you think we need to call an ambulance (=phone to ask an ambulance to come)?
MHTTCa special vehicle that is used to take people who are ill or injured to hospital the ambulance serviceambulance staff/crew/worker The ambulance crew removed him from the wreckage. the ambulance driverby ambulance Mike had to be taken by ambulance to hospital. Do you think we need to call an ambulance (=phone to ask an ambulance to come)?Examples from the Corpus
ambulance• She went to San Diego for an internship, where she met an ambulance driver named Jerry Tonelli.• Even the firemen and ambulance personnel, when they are called in to help, come under attack.• The action taken in London had an immediate affect elsewhere as ambulance crews began to protest at the Government's intervention.• He was seventy-eight and it took four ambulance workers and Jack to finally get him in the ambulance.• His order organized the first military ambulance task force.• Charity trailed after the crowd out to the ambulance.• I rode up to the ambulance and looked in.• The ambulance men arrived and immediately poured ice cold water over the burns.call an ambulance• After taking an overdose he told his neighbour what he had done and she called an ambulance.• They called an ambulance and he was helped into it.• The 86-year-old had to call an ambulance when her carer failed to turn up.• She would need to call an ambulance straight away.Origin ambulance (1800-1900) French “place near a battle where wounds are treated”, from ambulant “walking”, from Latin ambulare; → AMBLE 