a high-pitched tone range for a singing voice or a musical instrument, a person or instrument that performs in this range, or a part written for a person/instrument this range;
e.g. She is the strongest treble in the choir.
(adjective)
threefold, having three uses or parts;
e.g. The three students share a treble room in a dorm.
(adjective)
triple, occurring thrice, multiplied by three;
e.g. This price is treble of what it used to be.
(verb)
to multiply something by three, to make it three times as numerous or large;
e.g. This recipe serves four people, so you should treble it to feed twelve people.