'pneumotachometer' originates from Greek, specifically the elements 'pneuma' (πνεῦμα), 'takhos' (ταχός) and 'metron' (μέτρον), where 'pneuma' meant 'breath' or 'wind', 'takhos' meant 'speed', and 'metron' meant 'measure'.

'pneumotachometer' was formed in modern scientific English by combining the combining form 'pneumo-' (relating to air or lungs) with 'tachometer' (an instrument for measuring speed); it is closely related to and sometimes used interchangeably with 'pneumotachograph', a similar respiratory instrument coined in the 20th century.

Initially coined to mean 'an instrument for measuring the speed of air (especially in respiration)', the term has remained consistent and is now used more broadly for devices that measure respiratory airflow rates in clinical and research contexts.