The Collaborative International Dictionary of English v.0.48:
Bass \Bass\, a. Deep or grave in tone. [1913 Webster] Bass clef (Mus.), the character placed at the beginning of the staff containing the bass part of a musical composition. [See Illust. under Clef.] Bass voice, a deep-sounding voice; a voice fitted for singing bass. [1913 Webster]WordNet (r) 3.0 (2006):
bass voice n 1: the lowest adult male singing voice [syn: bass, bass voice, basso]