A celebration which comes to early, e.g. a premature cheer
In a heated beach volleyball match, LMU hit a killer shot to looked like it won the match for LMU so the LMU fans went wild, but Kat had an amazing one-armed dig to pop the ball over for the point against LMU, who was already celebrating their victory. The LMU team lost the point during their premacheer
noun: a loud cheer ejaculated loudly and involuntarily during a sporting event when one thinks his or her team gained some ground, when it really was a play that favored the other team.
Sitting in the Brazil section of the futbol staduim, Jose emitted a premacheer ejaculation thinking his team's goalie had made the save, when the ball had actually rolled in. The other Brazil fans beat him up for his mistake.