Green’s Dictionary of Slang

1. (Aus.) a cigar or cigarette [= smoke n. (2a)].

1970

Times Literary Supplement 16 Oct. n.p.: A man in an Australian pub will offer a sentimental, meaning a smoke or cigarette, though the verses of A Sentimental Bloke are probably not now much read.

2. (Aus. drugs) cocaine [coke n.¹ (1)].

2000

R.G. Barrett Leaving Bondi (2013) [ebook] ‘What did he do with all the money?’ ‘Shoved most of it up his nose.’ ‘Into the sentimental bloke, eh’.