Axilla
area of the human body beneath the joint between arm and torso / From Wikipedia, the free encyclopedia
The axilla (also known as the armpit, underarm, or oxter) is the area on the human body right under where the joint where the arm connects to the shoulder. The axilla is one of the four places where a medical thermometer can be used to measure human body temperature. The other places are the rectum, mouth, and ear canal.[1]