May refer to two things in English slang
(this is true for American
and subsequently (and sadly) Canadian
...unsure for British
). /msg me if yo know ;)
1. (vulgar) A synecdoche where the head of the penis represents the whole penis, thus the expression "Giving head." This in turn creates a metonymy which attributes "head" to blowjobs.
"Dude, he gives sloppy head! I can do way better."
2. The foam from the top of beer poured into a glass. This is usually used when there is a considerable amount of foam accumulated.
"Dude, this beer is ALL head! Wtf?"
"But...but...I don't understand...this is factual.../me runs away and cries."