"pertaining to Ionia," 1570s of music; 1580s of architecture, from Latin Ionicus, from Greek Ionikos (see Ionian).
ionic i·on·ic (ī-ŏn'ĭk)
adj.
Of, containing, or involving an ion or ions.
One of the three main styles of Greek architecture (the others are Corinthian and Doric). The Ionic column is slender and finely fluted; its capital is in the shape of a scroll.