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1.
A person you are friends with only because you work together. (A Co-Worker Friend). If one of you left the job, you wouldn't keep in touch.
"Ashley is my best Co-Friend, we take all our breaks and lunches together, but I would never ask her to hang out after work because friends and work don't mix."
by shrink03 January 09, 2012
 
2.
a friend who is only your friend at work
At work I do not have any friends, only co-friends and that is because friends at work do not mix.

Or
I only have one co-friend at work and that is Kendhal. We do everything together like take lunches and breaks together, we email each all the time but one thing we never do is hang with each other outside of work, because we are only friends at work.
by UrbanAsh January 11, 2012