It can't really be defined. Nojob is a word you can use for alot of stuff. Like people and deeds. In theory it means that someone who is a nojob won't get a job, or at least only get a bad one. Like a construction worker who used to smoke crack and didn't pay attention in school.
Guy1: Look, that guy is smoking weed in class!
Guy2: Hahhaha, what a Nojob!
Guy1 and Guy2 talks to another random guy at the start of a new school year. The random guy tells them that he used all his savings on cigarettes and that he got an F in some of the classes last school year. Guy1 and Guy2 walks away and Guy1 whispers "WTF! That's super nojob hahaha!"
The words etymology is old latin and was first noticed in 840 AD by a man named Swaut Dehucon. He spent his last years writing books about words found in teen subcultures around the Roman Empire. Swaut discovered the word in Athen while speaking to the local priest. The priest told Swaut about the worst word he had heard, a word a teenager once had said while attending church. At first Swaut didn't understand why the word was a bad word, but as the priest went on, Swauts eyes opened more and more.
Swaut decided to dedicate a good 10 pages of his first book to just this word. The word "Mats". Swauts book was never finished as he passed away too early, and as the years went on the book was forgotten. 15 years later when Swauts grandaugther went up to the loft on a random ocatiow
Now to the point you have all been waiting for, what doess this mean and bad word mean? Well here it goes: A man with a small dick. The word also gives the impression of "talking down" people with small penises. Thats why the priest thought it was such a bad word.
Girl 1 walks up to Girl 2
Girl 1 "I went out with that guy from Tinder yesterday"
Girl 2 "Ohhh, how did it go?"
Girl 1 "It was cool, until we went to bed. He was a mats ..."
Girl 2 "Hahaha"
Guy 1 walks up to Guy 2.
Guy 2 "Whats up?"
Guy 1 "Stfu"
Guy 2 "Wtf man, why so mean?"
Guy 1 "I heard rumors that you were a mats"
Guy 1 wwalks awawy awkwardly