a junkyard is an established male who doesn't shit from anyone... not even another junkyard dog. any female who is already intimately affiliated with a junkyard dog is called a "bitch". any feamle in pursuit of a junkyard dog is calssified as a bitch in heat.
"Hey dude aren't those the junkyard dogs over there?"
"Yea man watch out, they dont take shit from nobody, not even eachother, oh and i think those two girls with them are bitches."