An apparatus for inhaling any vapor or volatile substance, such as ether or chloroform, or an aerosol mist of a solution, for medicinal purposes; as, he alway carried his inhaler around in his pocket in case he had asthmatic attack. [1913 Webster]
A contrivance to filter, as air, in order to protect the lungs from inhaling damp or cold air, noxious gases, dust, etc.; also, the respiratory apparatus for divers. [1913 Webster]