Adrenalin

noun
  1. A hormone secreted by the adrenal glands that increases rates of blood circulation, breathing, and carbohydrate metabolism and prepares muscles for exertion; also known as epinephrine. noun
    The sudden noise triggered a rush of adrenalin, making her heart race.
    Adrenalin is often released in response to stress or fear, preparing the body for a 'fight or flight' response.
  2. A feeling of excitement and energy, often associated with a heightened state of alertness or activity. noun
    He felt a surge of adrenalin as he stepped onto the stage to perform.
    The thrill of the roller coaster ride gave her an adrenalin rush.