armpit

The axilla (also, armpit, underarm or oxter) is the area on the human body directly under the joint where the arm connects to the shoulder. It also contains many sweat glands.
In humans, the formation of body odor happens mostly in the armpit. These odorant substances have been suggested by some to serve as pheromones, which play a role related to mating. However, this is a controversial topic within the scientific community. The underarm regions seem more important than the genital region for body odor, which may be related to human bipedalism.

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