Verb: to utilize any and all objects around you in order to do something slightly useful, but more especially, just damned cool.
Usage:
1. "You locked my keys in the car! Well, do you have a piece of gum? We're just going to have to MacGyver our way in and get them."
2. "So we're going to die in a nuclear explosion! Well do you have a Zippo and some gum? Let's MacGyver ourselves a spaceship.
3. "So we're in Hell! Well, do you have a Zippo, a piece of gum, and a shoestring? We're just going to have to MacGyver our way back to Earth.