A very offensive word for someone who drinks a lot of alcohol. It is not a medical word and it is not kind. It names the person by the drinking, as if that is all they are. You will hear it in British and Australian English more than in careful American English. It can mean a drunk on a night out, or someone whose life is bent around drink; tone of voice decides how sharp it is, but the word itself is already meant to stain. Though actually, piss here is rough slang for alcohol, not a picture of urine, and -head is the same ending you meet in other insults that reduce a person to one habit. Do not use it about a classmate, a parent, or anyone you still have to look in the eye. If you only need the fact, say heavy drinker, they drink too much, or alcoholic when that is the true medical word.

酒鬼（罵人，極粗）