'bronchodilator' is formed from the combination of 'broncho-' (referring to the bronchi) and 'dilator' (something that widens or expands). 'Broncho-' comes from Greek 'bronkhos' meaning 'windpipe', and 'dilator' comes from Latin 'dilatare' meaning 'to spread out or enlarge'.

'Bronchodilator' was coined in modern medical English by combining the terms 'broncho-' and 'dilator' to describe substances that widen the bronchi. The word did not exist in earlier forms of English and is a product of modern medical terminology.

Initially, it specifically referred to any agent that dilates the bronchi, and this meaning has remained consistent in medical usage.