Axillae

The axilla (or armpit, underarm, or oxter) is the area on the human body directly under the joint where the arm connects to the shoulder.

The contents of the axilla include the axillary vein and artery, as well as the brachial plexus, lymph nodes and fat. Axilla is the space between the side of the thorax and the upper arm.

Terminology
The term "underarm" typically refers to the outer surface of the axilla. However, the terms are sometimes used interchangeably in casual contexts. Colloquially, armpit refers to an object or place which is smelly, greasy, hairy or otherwise undesirable.

The term oxter is most often used in the United Kingdom and the Republic of Ireland. In Northern Ireland "oxter" generally replaces all other names for the armpit.

Underarm hair
Underarm hair usually grows in the underarms of both females and males, beginning in adolescence. In modern Western culture, it is common for women to remove underarm hair for aesthetic reasons. As underarm hair grows quickly, shaving must be performed frequently, or else stubble will appear in the axilla.

Throughout the feminist movement, previously in the hippie culture, and in some areas of the punk rock scene, some women choose to keep their underarm hair for a variety of reasons, from subversion to egalitarianism to comfort. Conversely, some men choose to remove their underarm hair for similar aesthetic reasons or to reduce friction in some sports, such as swimming.

Axillary intertrigo
Excessive perspiration can result in axillary intertrigo. Intertrigo is an inflamed skin condition caused by heat, friction, and moisture. A warm, wet armpit may accommodate the growth of pathogenic bacteria, yeasts, and fungi. The condition is responsible for rash-like symptoms, pustules, or chronic itching or burning in the armpit. Axillary intertrigo is common among those who work in hot environments.

Miscellany

 * The axilla is one of the four sites (the other three being the mouth, rectum, and ear canal) in which a medical thermometer may be inserted in order to measure body temperature.
 * The underarms are among the locations in the human body which are most vulnerable to tickling.
 * The sexual attraction to the underarms is called axillism and/or also called as Armpit Fetish.