Green’s Dictionary of Slang

1. an ambulance.

1974		J. McClure Gooseberry Fool (1976) 155: If all the ambos weren’t out, he’d have been relieved by now.
1991		D. Simon Homicide (1993) 280: He looked pretty bad in the ambo.
1997		Simon & Burns Corner (1998) 54: She hates listening to the gunshots that echo from Fairmount and Gilmor at night, wondering if the ambo siren is for DeAndre.
2002		Simon & Burns ‘The Hunt’ Wire ser. 1 ep. 11 [TV script] She couldn’t talk, couldn’t breathe; she went into the ambo that way.
2004		P. Miller Looking After Your Ageing Parents 35: Mum was spitting chips about it. The ambos came and took her off.
2004		L. Redhead Peepshow [ebook] After the ambos the cops’ll come. I have to get out of here.
2021		P. Papathanasiou Stoning 15: ‘Cancel the ambo’.

2. an ambulance officer.

1991		R.G. Barratt ‘The Isn’t Union Bashing, But’ in What Do You Reckon (1997) [ebook] [N]urses, ambos and coppers, i.e., public servants who actually earn their money.
2000		personal correspondence 25 June n.p.: I see you know ‘ambo’, the person who rides in an ambulance. Normally used in the plural (the ambos came) and presumably a wise Australian replacement for ambulance person.
2013		‘Australia Day’ ad for MacDonalds cited crikey.com.au 10 Jan. 🌐 Here’s Gazza the ambo who’s pulled an all-nighter.
2019		C. Hammer Silver [ebook] ‘The ambos were there in no time. They’ll testify’.