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.
The fact of the matter is that any dog has the potential to bite. Different dogs have different triggers that spark them to act aggressive or different thresholds for which they will tolerate discomfort, pain, fear, or irritation. Fortunately, dogs often give warning signals that they are going to be aggressive.