Green’s Dictionary of Slang

1. an attractive, wonderful thing or person [honey n.¹ (1c)].

1896

Ade Artie (1963) 73: ‘Look at the new hat on her.’ [...] ‘It’s a hun.’.

2. a hundred, $100.

1895		E.W. Townsend A Daughter of the Tenements 236: ‘How much did you touch Waters for?’ Bill asked huskily. ‘For a hun.’.
1901		T.A. Dorgan in Zwilling TAD Lex. (1993) 110: Sam Hildreth casting a sorrowful glance at Owensbora who cost him ‘Five Hun’.