1825 (adj.), c.1830 (n.)., from Latin inhalantem, present participle of inhalare (see inhale).
inhalant in·ha·lant (ĭn-hā'lənt)
adj.
Used in or for inhaling. n.
Something that is inhaled, especially a drug that is delivered to the respiratory passages by a nebulizer or an aerosol container.