What does axillae mean?
Axillae is the plural of axilla and refers to the armpits — the hollow areas on either side of the body where each arm meets the shoulder. The term belongs chiefly to medical and anatomical vocabulary: clinicians examine the axillae to check lymph nodes, and the region houses sweat glands, nerves, and blood vessels traveling between the neck and arm. In botany, the word has a second life, describing the angles between a leaf stalk and the plant stem, where new buds commonly develop. Derived from Latin, axillae carries a formal, clinical register; ordinary conversation favors plain 'armpits' instead. It remains valuable vocabulary for anyone reading medical reports or botanical descriptions, offering a precise term for a part of the body everyone has but rarely names so formally.
nounThe plural of axilla: the armpits, or the hollow spaces beneath the junction of the arm and shoulder. In botany, it also denotes the upper angles between a leaf stalk (petiole) and the stem, where buds often form.
- Anatomy: the armpits; the paired hollow regions beneath each shoulder joint where the arm meets the trunk.
- Botany: the angles formed between a leaf's petiole and the stem above it, where lateral buds typically arise.
"The physician examined both axillae for swollen lymph nodes during the routine physical."
"Apoocrine sweat glands are concentrated in the axillae, which is why deodorant is applied there."
"In many shrubs, flower clusters emerge from the axillae of the leaves along the branch."
Axillae is itself the plural form; the singular is axilla, and the plural is standard in anatomical and botanical literature.
"Both axillae were inspected for signs of infection."
Your armpits have a proper Latin name — and doctors say it every single day.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of axillae
Axillae derives from the classical Latin noun axilla, meaning 'armpit', which itself is related to axis ('axle'), both tracing back to the same root denoting an axis or central pivot. Latin axilla entered English as a learned borrowing, with 'axilla' attested from around the early seventeenth century in medical writing. The adjective axillary shares this origin, as do cognate words built on the shared root such as axis and axle.
Related word forms
How axillae is actually used
Axillae is almost exclusively used in technical contexts — anatomy, medicine, and botany — rather than everyday speech. In casual English people simply say 'armpits'; 'axillae' appears mainly in clinical documentation, anatomical description, and scientific writing.
Easily confused with axillae
Axilla is the singular form referring to one armpit or leaf angle, while axillae is its plural referring to two or more.