I. treb ‧ le 1 /ˈtreb ə l/ BrE AmE predeterminer British English
three times as big, as much, or as many as something else SYN triple American English :
They sold the house for treble the amount they paid for it.
II. treble 2 BrE AmE verb [intransitive and transitive] British English
to become three times as big in amount, size, or number, or to make something increase in this way SYN triple American English :
Their profits have trebled in the last two years.
III. treble 3 BrE AmE noun
1 . [uncountable] the upper half of the whole range of musical notes ⇨ ↑ bass 1 (3)
2 . [countable] a boy’s high singing voice, or a boy with a voice like this
3 . [countable] the part of a musical work that is written for a treble voice or instrument
IV. treble 4 BrE AmE adjective [only before noun]
[ Date: 1200-1300 ; Language: Old French ; Origin: Latin triplus ; ↑ triple 1 ]
a treble voice or instrument produces high notes