sul·fite I. noun orsul·phite\ˈsəlˌfīt, usu -īd.+V\ (-s) Etymology:sulfite from French, alteration (influenced by -ite) (I) of sulfate; sulphite modification (influenced by sulphur) of French sulfite : a salt or ester of sulfurous acid • sul·fit·ic\|səl|fid.ik\adjective II. transitive verb orsulphite\“\ (-ed/-ing/-s) : to treat with sulfur dioxide, sulfurous acid, or a sulfite