Definition:

OUTDOORPHIN (out’dôr’fin) n.

A feeling of general well-being, happiness and energy that one gets when they are in the outdoors.

The word Outdoorphin comes from the two words, “outdoor + morphine.”  People claim that outdoorphins are non-addictive but I claim to differ!

Other terms:
The term outdoorphin rush refers to feelings of exhilaration brought on by breathing fresh air and basking in the sun!