'inhalation' originates from Latin, specifically the word 'inhalatio,' where 'in-' meant 'into' and 'halare' meant 'to breathe.'

'inhalatio' transformed into the French word 'inhalation,' and eventually became the modern English word 'inhalation' through Middle English.

Initially, it meant 'to breathe into,' but over time it evolved into its current meaning of 'the act of drawing air or other substances into the lungs.'