An annoying person who will one up anything that is posted on an online forum, message board or social network site. If you post an update about something they will try to top it with a personal story of their own. Also applies to posts about videos, links, etc., as they will tell you how your media is old, a repost, or how ________ is better than what you posted.
On Facebook:

Mike: Check out this funny ass video of a rabbit humping a football!

Brian: Old! Repost! Fail!

Mike: Man, Brian is a real Online One Upper, what a douche!
by horse-dong November 16, 2010
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