adrenaline
//əˈdren.əl.ɪn//
Noun
1
A hormone secreted by the adrenal glands that increases heart rate, blood pressure, and energy levels, especially in response to stress or danger.
When I saw the bear, I felt a rush of adrenaline.
2
A feeling of excitement, thrill, or heightened energy, especially in intense or risky situations.
I felt a rush of adrenaline as I jumped off the cliff into the water.