One who clearly loves a damn good session, and sending their head around the bend by consuming vast amounts of alcohol and/or various other substances (usually the latter)

Can usually be found talking codshit, raving, or dying in a hole.

Someone who is possessed by clout chasing. The original human is now gone and a demonic entity that feeds on clout is all that is left. An empty shell with no control of their actions, forced to blindly react to situations they think will bring them attention.

it comes from the french word for no job and fucked up
a mess head could do any drugs or just sniff packet meals?
someone who is so fucked they lick old newspaper cuttings for nutrition and one time they took so much pills they went back in time

A sick clothing line. Also can be used to refer to the wearer of said messhead clothing. Can also be used as an adjective to describe a person, though the connotation is neither good nor bad and entirely up for interpretation.

a man who does not shower for days, despite getting his dick sucked by a 250 lb hog. Therefore, his hair is messy due to a lack of showering and his smaller, more sensitive dome is tarnished with the remains of a man-juice-milkshake improperly guzzled by a fat troll.