The Spanish word 'espirometría' (spirometry) is a modern medical term formed by combining two ancient elements: the Latin 'spirare' meaning 'to breathe', and the Greek suffix '-metria' meaning 'measurement'. This hybrid formation literally means 'the measurement of breathing', which perfectly describes its modern usage as the measurement of lung capacity and breathing function.

Several simpler Spanish words share the Latin root 'spirare': 'espirar' (to exhale or expire), 'respirar' (to breathe), 'inspirar' (to inhale or inspire), and 'suspirar' (to sigh). All these words relate to different aspects of breathing, with 'espirometría' being the technical term for measuring this vital function.

Many English words share these same roots. From Latin 'spirare', we get words like 'spirit' (originally referring to breath as the essence of life), 'respire', 'inspire', 'expire', and 'perspire'. The '-metry' ending is found in many English measurement words like 'geometry' (measurement of the earth), 'symmetry' (measurement of sameness), and 'thermometry' (measurement of temperature). The direct English cognate is 'spirometry'.