armpit

from WordNet (r) 3.0 (2006)

armpit
    n 1: the hollow under the arm where it is joined to the
         shoulder; "they were up to their armpits in water" [syn:
         {armpit}, {axilla}, {axillary cavity}, {axillary fossa}]

from The Collaborative International Dictionary of English v.0.48

Armpit \Arm"pit`\, n. [Arm + pit.]
   The hollow beneath the junction of the arm and shoulder; the
   axilla.
   [1913 Webster]

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