gunch out

When someone backs out of previously made plans, especially because of attempts to thwart said plans by a gunch.

"Hey, did you and Jerome man slam that slut from the bar?"
"No, his girl called so he decided to gunch out...said he had to go to Antiques Roadshow or some bullshit. You can be the guy on the other side of the wall if you want."
"I'll bring the viking helmet."