It’s Short for Wigfield

Duane Reade cashier: Hey! Hey, security! What’s your name?
Duane Reade security: Huh?
Dunae Reade cashier: Your name, fool! What’s your name?
Duane Reade security: Wiggy.
Duane Reade cashier: What?
Duane Reade security: Wiggy. W-I-G-G-Y. That’s not my government name though.

–Duane Reade, Broadway & Canal

Overheard by: K. Thor Jensen