Green’s Dictionary of Slang

1. to enjoy oneself.

1692		C. Gildon Dialogue from Hell of Cuckoldom 15: S---nk me, Ned, I was always of thy Mind, as long as I could flutter abroad in my Glass Coach [...] D---me if I car’d a rush who rid in my Saddle.
1890–1904		Farmer & Henley Sl. and Its Analogues.

2. to gamble, to wager.

1883		‘’Arry on His Critics and Champions’ in Punch 14 Apr. 180/1: Young pidgins too funky to flutter, old roosters too stale to enjoy.
1895		Westminster Gazette 31 July 3/1: The three American girls [...] were seen [...] ‘fluttering’ for the upper berth in their cabin .
1905		Marvel III:61 14: Bet ye’re going to flutter.

3. (Aus.) to try something out.

1924

G.H. Lawson Dict. of Aus. Words And Terms 🌐 FLUTTER—To give a trial.