In music, alone; not combined with other voices or instruments of equal importance; not concerted. A solo passage may be accompanied, however, by voices or instruments of less importance.n. It. pl. soli (-li), E. pl. solos (-lōz).n. A melody, movement, or work intended for or performed by a single performer, vocal or instrumental, with or without accompaniment. Opposed to concerted piece, whether chorus, duet, trio, or for a number of instruments.n. A game of cards, played usually by four persons, with a euchre pack.n. In card-playing, a bid to play without a partner or without discarding from the hand, as in solo whist and skat.