Of, pertaining, or relating to the Iones or Ionians as a race, or to one of the regions named from them, Ionia or the Ionian Islands: as, the Ionic dialect or school; the Ionic order.In ancient prosody, constituting a foot of two long syllables followed by two shorts, or vice versa; pertaining to or consisting of such feet: as, an Ionic foot, colon, verse, or system; Ionic rhythm.n. In prosody: An Ionic foot.n. An Ionic verse or meter.In physical chemistry, of or pertaining to an ion or the ions which carry an electric current in electrolysis: see Arrhenius's theory of electrolytic or ionic dissociation.