: relating to, being, or causing physiological changes in the body (as an increase in heart rate or dilation of bronchi) in response to stress <epinephrine is a fight–or–flight hormone> <a fight–or–flight reaction>
First Known Use of FIGHT-OR-FLIGHT
Seen & Heard
What made you want to look up fight-or-flight? Please tell us where you read or heard it (including the quote, if possible).