What does "basso" mean?

Basso: (a) The bass or lowest part; as, to sing basso. (b) One who sings the lowest part. (c) The double bass, or contrabasso. Basso continuo (. Etym: [It., bass continued.] (Mus.) A bass part written out continuously, while the other parts of the harmony are indicated by figures attached to the bass; continued bass.