the purple head is the tip of the penis, more noticeable if you have been circumcised

A term used to reference cannabis/marijuana/weed.

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.

The purplish looking thing underneath your foreskin.
Very sensitive to prods and pokes, especially with needles and pencils.

when you are getting dome so good you forget to breathe, thus causing your head to turn purple

The Top Purple Part of a Circumcised Penis.

A strain of marijuana thus named for the purple hue of its matured buds. Arguably the source of Hendrix's Purple Haze ditty (don't quote me on that).