Originally, slang for headlice in a hat...
Nitty can now mean pretty much anything you like :)

Nickname for the name "Anita"

Little man-titties.

A snakey guy who thinks he’s on piss but isn’t, full on nerd, ain’t rated in ends

Means nothing, nutin, nada,etc.

Someone who is overly obsessive, annoying, jealous, irrelevant, attention seeking, just a general nuisance and waste of life aka a campaign of pro choice.

someone who likes to smoke a faggy waggy when they are bored