Other forms: armpits
The armpit is the hollow under the arm at the shoulder. Under the armpit, shave the armpits, an armpit stain.
The lymph nodes there are checked in breast cancer because that is where the drainage goes, which is why an examination reaches into it. Sweat there has no smell until skin bacteria work on it. Calling a place the armpit of somewhere is an insult.
1nounarmpitThe hollow under the arm at the shoulder.
“The shirt was too tight under the armpits, so I took it back.”
armpit is a body part.
Arm plus pit, from Old English pytt, a hollow. The compound is recorded from Middle English.
Middle English
armpitt
English, today
armpit
From Middle English armpitt, arme-pitt, armput, equivalent to arm + pit. something unpleasant Presumably a reference to underarm body odor.
Etymology from Wiktionary, CC BY-SA