A combination of the words rem (from remedial) and reject. A slang term used to describe someone who is not well liked, with no friends and is also rather dumb.
"Did you see that guy sniffing his fingers when he came out of the toilet?"
"Yeah, what a remject."
While the trucker was being hassled by a cop that sarcastically addressed him as sir, the offended driver invoked sir-rejection and said, "Don't call ME sir, I work for a living."
When a user submits a new word and definition to Urban Dictionary and the volunteer editors who happen to review the submission lack intelligence, understanding and/or a sense of humour therefore end up prematurely rejecting spectacularly humorous submissions.
Editor - "A few volunteer editors read your definition and decided to not publish it. Don't take it personally"
Disappointed user - "Damn it, premature Rejectulation again!"
guy #1: urban dictionary rejected my definition for "George Tabuki"
guy #2: you should just post those urban dictionary rejected words on unurbandictionary.blogspot.ca
guy #1: I definitely will.