Green’s Dictionary of Slang

angler n.

[fishing imagery]

1. [mid-16C–19C; 1970s+] (UK Und., also anglero) a thief who uses a pole, the angling stick, with a hook at one end to ‘fish’ items from open windows, unguarded market stalls, passing carts etc.

2. [early 18C] (UK Und.) a pickpocket; thus angle, to pick a pocket.

3. [late 18C–early 19C] (Und.) a petty thief, working in the street and always on the lookout for opportunities to commit small larcenies.

4. [late 18C–mid-19C] (UK/US Und.) a confidence trickster.

5. [mid-19C] (UK Und., also starrer) a smash-and-grab thief; also ext. as anglers in troubled water.