A word very friggin' difficult to define. Can mean different things in different countries and at different times. In America right now it refers to a person supporting left-wing economic and social policies.
verb, to cobble together a working piece of machinery or electronics from spare parts and duct tape using only your wits, folksy engineering knowledge (garnered from the scouts or your grandpa), and your swiss army knife
derived from the TV show in which the main character, MacGyver, did this every week in order to save the world and get the girl
I dropped by cd player on the concrete and it broke, so I had to macgyver it. It ain't pretty but it works.