1630s, "to smoke" (tobacco), from vapor + -ize. Later "convert into vapor, cause to become vapor" (1803), and "spray with fine mist" (1900). Intransitive sense "become vaporous" is from 1828. Related: Vaporized; vaporizing. An earlier verb was simply vapor (c. 1400, transitive and intransitive), from Latin vaporare.
