Literally, masterbation (male). As in penis = gerkin pickle. Figuratively, not doing anything constructive. Wasting
time, either by your own volition, or by another's. Spending
time doing something unworthwhile, or incorrectly.
"You were supposed to be working on the new
project, but nothing has been done! What have you been doing the last
three hours?"
"Shirkin' my gerkin."
or
"So I'm waiting for Shelly to finish getting dressed so we can go out, and I end up sitting in the living room with her
parents, just shirkin' the gerkin for a whole hour!"