Definition from Wiktionary, the free dictionary
Deliberate corruption of co-worker.
cow-orker (plural cow-orkers)
- (derogatory) co-worker
- 1989, Charles Anderson, Re: Words (mundane), alt.sca, 
- The above quote has been rated as gross, digusting, and tacky by my cow-orkers at work...are you a cow orker?
- 1998, cluelessnewbie, Re: I give up on alt.slack, alt.slack, 
- At this point, my cow-orker got real pissed off and firmly and courageously said: Hey, as a result of channeling, I discovered I used to be a cow in a previous lifetime.
- 2006, Richard Bos, Re: Casting malloc (was: Reading a string of unknown size), comp.lang.c, 
- You must be a popular cow-orker.
- 1989, Charles Anderson, Re: Words (mundane), alt.sca,