Green’s Dictionary of Slang

buzzer n.1

[buzz v.1 (3)]

1. [late 18C+] a pickpocket.

2. [late 19C] (UK Und.) a confidence trickster, who fools a shopkeeper into parting with a gold sovereign using sleight of hand and some hidden wax.

3. [1930s] (Aus. Und.) a robber of drunks; thus buzz a hoy, to rob a drunk.