When a bunch of zits appear in a small, focused group, in such a way that they appear to be one ginormous zit. Similar in appearance to a volcano or a small, very angry face.
Not to be confused with clusterfuck.
Stereotypical male 1: "DUDE, is that volcano on your face?"
Stereotypical male 2: "Nah, bro, it's a clusterzit."