Any text messagesent with intent to elude undesirable social situations.
"Uh, I can't believe this girl is texting me about hanging out with her and her lamefriends tonight. I'm gonna send her a rejext and hang with the guys instead."
To get rejected and/or turned down via text message; other forms include "rejexting" (the act of sending someone a rejecting text message), and "rejected" (past tense of rejext)
<girl looks at her phone> "He is such a douche! We went on two dates and he didn't even have the balls to dump me in person - he rejexted me!"
Refusing to being called sir because you don't think your better than others.
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!"