What is the meaning of Inhaler?

One who inhales.

A device with a canister holding medicine (either in powder or gas form) which is sprayed and inhaled by the patient, often for treating asthma and other respiratory diseases.

overtaker (a driver who overtakes another vehicle)

inhaler

to inhale

first-person singular present passive subjunctive of inhālō

imperative of inhalere

Source: wiktionary.org