noun (n)

• the hollow under the arm where it is joined to the shoulder

  lembah di bawah lengan tempatnya bergabung ke bahu

  Example:
  They were up to their armpits in water.
  

  Synonym:
  axilla, axillary cavity, axillary fossa
  

  source: wordnet30
• The hollow beneath the junction of the arm and shoulder; the axilla.

  lembah di bawah persimpangan dari lengan dan bahu; the axilla.

  source: webster1913