having a play of lustrous rainbow-like colors; "an iridescent oil slick"; "nacreous (or pearlescent) clouds looking like mother-of-pearl"; "a milky opalescent (or opaline) luster"
characteristic of informal spoken language or conversation; "wrote her letters in a colloquial style"; "the broken syntax and casual enunciation of conversational English"
uttered through the medium of speech or characterized by speech; sometimes used in combination; "a spoken message"; "the spoken language"; "a soft-spoken person"; "sharp-spoken"