axilla

ax·il·la

noun \ag-ˈzil-ə, ak-ˈsil-\

plural ax·il·lae \-(ˌ)ē, -ˌī\ or ax·il·las

Definition of AXILLA

: the cavity beneath the junction of the arm or anterior appendage and shoulder or pectoral girdle containing the axillary artery and vein, a part of the brachial plexus of nerves, many lymph nodes, and fat and areolar tissue; especially : armpit