My definition – adrenaline is a chemical in the body that surges in response to a threat or stressor. There have been claims that adrenaline can help women lift entire cars off of their children.
Real definition – according to Wikipedia, “Epinephrine, also known as adrenalin or adrenaline, is a hormone, neurotransmitter and medication. Epinephrine is normally produced by both the adrenal glands and certain neurons. It plays an important role in the fight-or-flight response by increasing blood flow to muscles, output of the heart, pupil dilation, and blood sugar.” Also, adrenalin causing hysterical strength a common anecdote but has not been proven scientifically.