The Collaborative International Dictionary of English v.0.48:

Inhalant \In*hal"ant\, a. [Cf. F. inhalant.]
   Inhaling; used for inhaling.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Inhalant \In*hal"ant\, n.
   An apparatus also called an inhaler (which see); also, that
   which is to be inhaled, especially a medicine taken by
   inhalation.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

inhalant
    adj 1: inhaling or serving for inhalation; "an inhalant pore"
    n 1: something that is inhaled
    2: a medication to be taken by inhaling it [syn: inhalant,
       inhalation]

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "inhalant":
   balm, balsam, drops, drug, electuary, elixir, ethical drug,
   generic name, herbs, lincture, linctus, materia medica, medicament,
   medication, medicinal, medicinal herbs, medicine, mixture,
   nonprescription drug, officinal, patent medicine, pharmacon,
   physic, powder, preparation, prescription drug, proprietary,
   proprietary medicine, proprietary name, simples, syrup,
   theraputant, tisane, vegetable remedies