What does axilla mean?
The axilla is the anatomical name for the armpit — the pyramidal hollow beneath the joint where the arm meets the shoulder. In medical settings it matters far more than its humble everyday identity suggests: the axilla contains lymph nodes that are routinely examined for signs of infection or breast cancer, major nerves and vessels of the upper limb pass through it, and it serves as a standard site for measuring body temperature, particularly in infants. Clinicians speak of axillary lymph nodes, axillary dissection in breast surgery, and axillary temperature readings, so the word and its adjective 'axillary' appear constantly in clinical literature. The term comes from the Latin 'axilla', meaning armpit, and entered English as part of the classical vocabulary of anatomy in the seventeenth century. Though formal in register, it is precise, well established, and indispensable to medicine.
The hollow or cavity beneath the junction of the arm and shoulder; the armpit, especially regarded anatomically as a region containing lymph nodes, blood vessels, and nerves.
"The surgeon made a small incision in the left axilla to remove a sentinel lymph node."
Standard plural in medical writing is 'axillae'; 'axillas' also occurs. The derived adjective is 'axillary'.
An analogous region in animals, such as the underside of a bird's wing near its base.
"The ornithologist noted patches of colour in the bird's axilla while examining the wing."
Less common than the anatomical sense; chiefly used in ornithological description.
Both the Latin plural 'axillae' and anglicised 'axillas' are accepted; 'axillae' is strongly preferred in medical literature.
"Bilateral axillae were examined and no lymphadenopathy was found."
In Latin, 'axilla' literally means 'little wing' — the Romans saw your armpit as a tiny wing folded under your arm.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of axilla
Axilla comes directly from the Latin 'axilla', meaning 'armpit', which is thought to be a diminutive related to 'ala', meaning 'wing' or 'armpit'. The word was adopted into English in the early modern period, appearing in anatomical texts from around the first half of the seventeenth century, when Latin terminology was being systematically incorporated into medical vocabulary. Its botanical cognate 'axil' describes the corresponding angle between a leaf and stem, reflecting how anatomists and botanists drew on the same descriptive language.
Related word forms
How axilla is actually used
Axilla is a formal anatomical and medical term; everyday English speakers simply say 'armpit'. It appears almost exclusively in clinical, surgical, and scientific contexts, and its Latin-derived plural 'axillae' is standard in medical writing.
Easily confused with axilla
An axil is the angle between a leaf and a stem in botany, whereas an axilla is the human armpit in anatomy; both derive from the same Latin root.