Green’s Dictionary of Slang

(Aus./N.Z.) a vagrant’s swag or pack.

1905		Bulletin (Sydney) 14 Dec. 27/4: He was sittin’ down on Matilda, lookin’ fair done in, reg’ler dead beat. [...] ‘Where are yer makin’ for? If it’s on my track, I’ll give you an’ Tilly a lift,’ sez I. ‘Blowed if I know,’ sez he.
1906		Truth (Wellington) 24 Feb. 5: After 8 hours with Tilly up, our destination loomed up at last [AND].
1927		Bulletin (Sydney) 23 June 19: With my old sootcoated billy an’ my leather-twisted Tilly I can laugh at every collared city swell.