purple head: the bell shaped extrusion at the out-ward facing end of a penis. at the summit of un-mutated purple heads lies a hole (usually called an 'eye') that continues through the penis and into the body. a white fluid is ejaculated out of the eye of a purple head.
Purple head is when a girl pulls on a guy's dick so hard while sucking that it causes his head to turn purple.
My girlfriend Debra and I wanted to take our relationship the the next level last night and so she asked me if she could suck my dick. Since I was feeling horny, I pulled my pants down to my ankles and let her do her job. She started to suck on it and felt good. Ten minutes later, it started to get rough and so she took her hand and gave my dick a good tug. She pulled on it so hard that I screamed. My face turned purple. It was the worst night of my life. Purple head really hurts.