Armpit

Part of speech: noun

Pronunciation: /ˈɑɹmˌpɪt/

Definitions

1. The hollow area beneath the joint where the arm connects to the shoulder
2. The recessed area located beneath the upper limb's junction with the torso serves as both a physical and anatomical region for various biological functions
3. This anatomical space underneath the shoulder joint facilitates arm movement while also being home to various sweat glands

Etymology: Armpit is one of those compounds whose parts tell you exactly what it means: "arm" plus "pit", the pit being the hollow beneath the shoulder where the arm joins the body. Middle English speakers used "armpitt" and variants like "arme-pitt" and "armput" for the same hollow. The "pit" element is old and sturdy in English, meaning a hole or depression in the ground, and it was applied to body parts with similar dips, which is why the armpit shares a name with a hole in the earth. The word's sense has a less flattering side. Dictionaries note that the term is presumably a reference to underarm body odor, the smell that gives the spot its unpleasant reputation. That association is widely assumed rather than documented, so the grim pun on "pit" as an unpleasant place is a plausible reading, not a settled fact.

Synonyms: axilla, underarm