Someone who is Sick (in the) Head.
Hence Sick Head.
This is a person who tends to do crazy dangerous and slightly harsh things. This involves getting in fights and going crazy.
(See Jack Brett)
I wouldn't start on that guy he is a sick head, and will put you on the floor
Somebody who is deceptive, ignorant or otherwise unpleasantly cunning. Not a friendly, jovial term, a Sackhead is very much similar to a dickhead, in which said person is claimed to have a penis, or in this case a (Nut)'Sack' upon their head.
equal meaning to dickhead; someone who feels humiliation because of committing an accidental act of embaressment; someone who is wrong after they were positive of being right; someone who is irritating
Guy #1: Shit, I just spilled my drink everywhere.
Guy #2 Ahhh, snickhead!
Guy #1: Damn, I was completely wrong.
Guy #2: Ahah, you a snickhead.
When your girl pulls a nylon stocking down over her head and sucks your dick. The feel of her nylon lips and wet silky tongue against your shaft is such a rush. It also catches most of the spooge so she can choose to eat it or wear it.