Green’s Dictionary of Slang

roaring horsetails n.

[rhy. sl.]

(Aus.) Aurora Australis.

[UK]Morris Austral Eng. 390/2: Roaring Horsetails, n. a slang name for the Aurora Australis.
[Aus]Baker Aus. Lang.
[Aus]Pete’s Aussie Sl. Home Page 🌐 roaring horsetails: Aurora Australis .