I. noun 1. the lowest adult male singing voice. 2. a singer with a bass voice. 3. a part written for a bass voice. 4. [as modifier] — denoting the member of a family of instruments that is the lowest in pitch • a bass clarinet.
5. a bass guitar or double bass. 6. [ mass noun] — the low-frequency output of a radio or audio system, corresponding to the bass in music. II. derivatives bassy adjective
– origin late Middle English: alteration of base2, influenced by basso.