The chemical in a woman's body that causes her to be the loudest thing in the vicinity. It is released by anger, usually by men.
Note that women are not physically altered by vagrenaline, unlike adrenaline released by men.
So, I have Jill the money to go and pay the electric bill last week. Now, our power's turned off. It turns out, she went out and bought a coach bag with that money. When I confronted her about it, her body released its vagrenaline, and she just started screaming at me, which was painful on the ear drums, so I just went to Jiggles.