Main Entry:

oc·tave

Pronunciation:

\ˈäk-tiv, -təv, -ˌtāv\

Function:

noun

Etymology:

Middle English, from Anglo-French, from Medieval Latin octava, from Latin, feminine of octavus eighth, from octo eight — more at eight

Date:

14th century

1: an 8-day period of observances beginning with a festival day2 a: a stanza of eight lines : ottava rima b: the first eight lines of an Italian sonnet3 a: a musical interval embracing eight diatonic degrees b: a tone or note at this interval c: the harmonic combination of two tones an octave apart d: the whole series of notes, tones, or digitals comprised within this interval and forming the unit of the modern scale e: an organ stop giving tones an octave above those corresponding to the keys4: the interval between two frequencies (as in an electromagnetic spectrum) having a ratio of 2 to 15: a group of eight