Definition of adrenaline
: epinephrine
Note:
Adrenaline is used in both technical and nontechnical contexts. It is commonly used in describing the physiological symptoms (such as increased heart rate and respiration) that occur as part of the body's fight-or-flight response to stress, as when someone is in a dangerous, frightening, or highly competitive situation, as well as the feelings of heightened energy, excitement, strength, and alertness associated with those symptoms.
In figurative use, it suggests a drug that provides something with a jolt of useful energy and stimulation.
