treble2

noun

• 1a high-pitched voice, especially a boy’s singing voice: the boy replied in a shrill treble [as modifier]:the children’s treble voices
• a boy (or girl) with a high-pitched singing voice: we had sung together as trebles in the choir
• a part written for a high voice or an instrument of a high pitch: we have studied the treatment of melodic lines in treble and bass separately

• 2 [as modifier] denoting a relatively high-pitched member of a family of similar instruments:a treble viol
• (also treble bell) the smallest and highest-pitched bell of a ring or set.

• 3 [mass noun] the high-frequency output of a radio, or audio system, corresponding to the treble in music.