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.
As a noun adrenaline is adrenaline. As a verb ad is (second person singular present form of the negation verb).
Figuratively, the term adrenaline is used in speaking of a high state of excitement: ?When the race began, the adrenaline really started pumping.?, If dictionaries list a word as both a noun and a verb , or you have heard or read it used that way often, then it is an established meaning and you can use it yourself without causing confusion. Though I'd note that, like many things with language, some usages are common and accepted in informal speech but considered inappropriate for formal writing.;"
