A term used mostly by gay men to depict something unpleasant, foul, or undesirable. Often replaces words such as stupid, dumb, gay, etc. Ugh, this is so vaginal, I have to work a 9 hour shift today! Those pants are straight up vaginal.
Warning signs such as fear and/or nervousness around other dogs, displays of aggression only under certain circumstances (while on leash, in the presence of food, in the presence of the owner, etc.), or most commonly, over-the-top play behavior can be seen at any stage of the dog's development.
Yes, Chows are considered an aggressive breed. Owners of aggressive breed dogs should know their dog and know them WELL. Keep in mind, though, that there is always some reason for a dog attack.