octave

noun

oc·​tave ˈäk-tiv 

-təv,

-ˌtāv

1

: an 8-day period of observances beginning with a festival day

2

a

: a stanza of eight lines : ottava rima

b

: the first eight lines of an Italian sonnet

3

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 keys

4

: the interval between two frequencies (as in an electromagnetic spectrum) having a ratio of 2 to 1

5

: a group of eight

Examples of octave in a Sentence

He sang the song an octave lower.

Recent Examples on the Web

Joined with the higher octave of Venus, Neptune can lead us down the road of passion, desire, and unconditional love. —Lisa Stardust, Refinery29, 27 Mar. 2025

The orchestration is a touch grotesque, with the first violins given a shrill D two octaves above middle C. —Alex Ross, New Yorker, 23 June 2025

Callas could sing three octaves, but the film is mostly one note. —Amy Nicholson, Los Angeles Times, 28 Nov. 2024

After a bit of trial and error, the team induced the cicadas to produce specific musical notes over more than three octaves, ranging from 27.5 hertz to 261.6 hertz. —Jennifer Ouellette, ArsTechnica, 2 May 2025

Word History

Etymology

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

First Known Use

14th century, in the meaning defined at sense 1

Kids Definition

octave

noun

oc·​tave ˈäk-tiv 

-təv,

-ˌtāv

1

: a group of eight lines of poetry (as the first eight lines of a sonnet)

2

a

: the difference in pitch between the first and eighth tone on the scale

b

: a tone or note that is eight steps above or below another note or tone

3

: a group of eight