winjoiner 

In eg. Quake 3 Arena a person who joins the other team even though their score is much higher and are likely to win is called a winjoiner. A winjoiner is not very well seen by other players.

WTF?! Egghead winjoiner! Kick him!

winjoiner by Micke September 14, 2006

win joiner

a term used in online games describing a player joins or switches to the side that is winning
this is frowned upon in many gaming communities, especially when it gives the winning side a 2+ player advantage

kick the noob win joiner!

win joiner by uncle sam December 29, 2008

winjoin 

A verb meaning to purposely join the winning side in a team vs. team video game match. It's usually done by a scrub who wants to make sure the better players are on his or her own team.

You fuckin noob! Why do you always come in here and winjoin and then you ragequit if you can't?!

winjoin by I_source_I December 16, 2012