rare. [f. TREBLE a. + -NESS.]
† 1. Treble quality (of sounds); high pitch.
1626. Bacon, Sylva, § 183. The Just and Measured Proportion of the Aire Percussed, towards the Basenesse or Treblenesse of Tones, is one of the greatest Secrets in the Contemplation of Sounds.
2. The quality of being threefold.
1888. in Cassells Encycl. Dict.