a person that is called in by a team to play for that selected team even when he is not allowed to play with that selected team because of improper registration, age, zone variance, grades, membership, or anything that would make him ineligable. The cirquis of the team always has more skill then then actual team he plays for. This person is normaly called in when a select team sees their oppenent and they realize that they can't beat them, so they call the cirquis in to help them out, because without him, they are sure to fail. From the outside looking in no one would ever know that he was not supposed to be playing. He looks like he belongs on the team by wearing their colors, logo, uniform, etc.
"Dude that guys a cirquis! He's not even supposed to be playing! Mann... maybe we can get him to play for our team sometime..."
They call him a cirquis because he is like a freak show, he does everything in the circus by himself that would normally take an entire set of performers to do and completes the acts flawlessly and often better than the individual specifically trained to do the task at hand.