Emily Dickinson Lexicon

ALT, or AL'TO, a. [It. from L. altus, high; Celt. alt, ailt, a high place; Heb. עלית, upper, על, high.]

In music, a term applied to high notes in the scale. In sculpture, alto-relievo, high relief, is when the figures project half or more, without being entirely detached from the ground. – Encyc. Cyc.