armpit - Wiktionary, the free dictionary

From Middle English armpitt, arme-pitt, armput, equivalent to arm +‎ pit.

(something unpleasant): Presumably a reference to underarm body odor.

• (US) IPA^(key): /ˈɑɹmˌpɪt/

armpit (plural armpits)

2. The cavity beneath the junction of the arm and shoulder.

   • 2009, Sarah Waters, The Little Stranger, Virago Press (2018), page 265:

     She stood a couple of feet away from me […] exposing an edge of brassière strap at her armpit―exposing the armpit itself, a muscular hollow shadowed with fine stubble and faintly streaked with talcum.

   • 2018 February 2, Owen Guo, “Aiming at China’s Armpits: When Foreign Brands Misfire”, in The New York Times‎^[1]:

     Unilever brought its Rexona deodorant to China a decade ago, dreaming of a market with 2.6 billion armpits.

   Synonyms: underarm; axilla (anatomy); oxter (UK, dialectal), armhole (UK, dialectal)

   Coordinate term: poplit (knee pit)

4. (colloquial, derogatory) Somewhere or something unpleasant or undesirable.

   Synonyms: butthole (vulgar), asshole (vulgar)

   the armpit of America

• Primat, impart