Someone who is like the character Severus Snape, from the Harry Potter series. Usually, it refers to someone being particularly sarcastic and distainful, and generally downright mean.
"Man, my chem teacher was all Snape-ish today."
"Did he tell the whole class you forgot your homework again?"
"Yeah, and he followed up with a sick burn, too!"
1. Sheesh, how straight forward do you want it to be? Break it down into two words: "fan" and "fiction". As in, Fiction written by overly-obsessed fans of books. Get it?
And you had to go on this site to look it up? Loser.
2. Fiction written by fans (durr) who usually don't have a life and wish they were the author of the book they're writing fiction about. Yay them, huh?
Oh, and that's not all. Usually, their writing is pretty bad with grammar mistakes, misspellings of characters (main or not), and cliched events that don't follow the actual events in the origin of their writing. Wonderful *rolls eyes with a voice full of sarcasm*.
1. Harry Potter decided to steal Dudley's computer and go on Urban Dictionary to look up naughty words he overheard that Voldemort and Snape were acting out, until he found the word "fanfiction". He decided to look it up because he had no clue what it was (the loser) and BAM! He realized he's a loser because he couldn't define the word "fanfiction". Kinda like you. Woot woot. Case closed. Next.
2. Oh, but despite the fact that he's a loser for looking up such a dumb word, Harry Potter didn't stop there. He went on a fanfiction site to write his own fanfiction about his life (a.k.a. books by JKR). I feel sorry for him, but hey, it's not my life that's getting screwed up by fanfiction and loser-ish-ness, so I don't give!