1. To split and continue on in a different direction. The road's going to fork off to the right in a couple of miles, which will lead you to our cabin. Several people in the group forked off to explore the other side of the mansion.
2. A humorous euphemism for "fuck off," an otherwise very rude and aggressive way to tell someone to go away. Fork off, will you? I don't want to hear any more of your ridiculous conspiracy theories. A: "Did you actually think your singing sounded good there?" B: "Oh, just fork off."
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.