A redundant defintion occurs when someone submits a word to the Urban Dictionary that has already been published. This can either be caused by failing to look up the word before submitting it or by a dumbass who doesn't care if the word is already in the UD.
This term does not apply to an entirely different meaning or to a rebuttal defintion, but to a definition that is almost or exactly the same as a previous entry.
There really is no legitimate excuse for redundant definitions!
For examples of a redundant definition just look up Obama. There are several Obama definitions that are word-for-word indentical! There is no excuse for THAT kind of bullshit!