a ‧ dren ‧ a ‧ lin BrE AmE , adrenaline /əˈdren ə l-ən, əˈdren ə l-ɪn/ noun [uncountable]
[ Date: 1900-2000 ; Origin: adrenal 'of or on the kidneys' (19-21 centuries) , from renal ; because adrenaline is produced by the adrenal glands ]
a chemical produced by your body when you are afraid, angry, or excited, which makes your heart beat faster:
There’s nothing like a good horror film to get the adrenalin going (=make you feel nervously excited) .