Green’s Dictionary of Slang

1. (Aus.) to hit.

1915

Bulletin (Sydney) 2 Sept. 26/1: The night afore last one of the guns from the den up the alley whooshed me a bonzer on the mush with a duster.

2. (UK Black, also woosh) to shoot (with a shotgun or machine pistol); thus w(h)oosha, a gun.

2015		67 ‘Skengs’ 🎵 Anybody talking about beefing the 6 can get whooshed down by the mac.
2016		67 ‘Money Afi Make’ 🎵 Got the German luges in the German / Run a man down with the woosha.
2018-20		T. Thorne (ed.) ‘Drill Slang Glossary’ at Forensic Linguistic Databank 🌐 Woosh - shoot.