'axilla' originates from Latin, specifically the word 'axilla', which is a diminutive of 'axis', where 'axis' meant 'axle' or 'pivot'.

'axilla' passed from Latin (and Medieval/Late Latin usage) into scientific and medical Latin and then into English as the modern term 'axilla'.

Initially, it meant 'little axis' (a small axle or pivot), but over time it evolved into its current anatomical meaning of 'armpit' (the hollow beneath the arm and shoulder junction).