cow orker: n.
alternatively: cow-orker

[Usenet] n. fortuitous typo for co-worker, widely used in Usenet, with perhaps a hint that orking cows is illegal. This term was popularized by Scott Adams (the creator of Dilbert) but seems to have originated earlier in a 1997 ScaryDevilMonastery.

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References: Original http://www.science.uva.nl/~mes/jargon/c/coworker.html