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

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

Designed for mixing, mastering and editing, the DT 1990 PRO MKII headphones produce a natural and spacious soundstage with accurate bass response, even in the lowest octaves, according to beyerdynamic. —Mark Sparrow, Forbes, 29 Oct. 2024

The sounds emitted can create a range of octaves, some even too complex for the human ear. —Moná Thomas, People.com, 24 Apr. 2025

In terms of octaves, New World monkeys can span three, while most human voices can barely extend beyond a single. —Paul Smaglik, Discover Magazine, 3 Apr. 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