oc‧tave /ˈɒktəv, ˈɒktɪv, -teɪv $ ˈɑːk-/ noun [countable]
[Date: 1300-1400; Language: Medieval Latin; Origin: octava, from Latin octo 'eight'; because there are eight notes in the range]
a) the range of musical notes between the first note of a scale and the last one
b) the first and last notes of a musical scale played together

[TahlilGaran] Dictionary of Contemporary English ▲