colloquially used to describe a person with a penchant for lying flat on their back and offering their face as a female's chair or resting place in anticipation of the double-glazing that will hopefully follow, generally for the entertainment of others and occasionally in exchange for money.
A person or group of people that travel from one unclaimed seat to another (normally at sporting events) because their cheap asses couldn't fork up the money for better seats. Said people are forced to move once seats are claimed by the rightful ticket holders.
Move it seat gypsie, I paid good money for those spots!!