A (usually intense) fight between two people, usually women. Two or more bitches fighting, most likely verbally.
The first section of this compound word (bish) is a commonly used form of the word bitch, which pretty much means the same thing. Spelt properly, it is a bitchfight.
Marco: Hey man, did you see Sarah and Kate yesterday? It was a total bishfight!
Ken: Whoa, you mean I missed it? Must have been intense, knowing those two.
Derived from the verb 'to Emily Bishop'. Used when someone is being horrendously boring past the point of no return and you're falling asleep because they have no personality what so ever.
See also: Roy Cropper/'Roy Croppering', the male equivalent.
Why are you Emily Bishoping? Yawn til dawn, i've had better raves with Emily Bishop. Maybe consider getting a newpersonality.