"apparatus to reduce liquids to a spray or mist," 1865, agent noun from atomize (q.v.).
Entries linking to atomizer
atomize v.
1829, "reduce to atoms;" by 1860, "reduce a liquid to a very fine mist;" a verb formed from atom + -ize. Related: Atomized; atomizing. Originally in reference to medical treatment for injured or diseased lungs. A sense of "to destroy with atomic weapons" is attested from 1945.