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

That's when Mercury gives full rein to his operatic urges as the song builds to a purposefully ludicrous crescendo with its references to Scaramouche (a Commedia dell'arte stock character) and octave-hopping Galileos. —Ed Masley, AZCentral.com, 21 Nov. 2025

It’s completed with a depiction of his four-octave range. —Larisha Paul, Rolling Stone, 18 Nov. 2025

Craig never had managed or coached baseball at any octave. —Nick Canepa, San Diego Union-Tribune, 8 Nov. 2025

As the sweetly melodic ballad tapers, a gentle beat kicks in and Carey vocalizes words of religious praise over a syncopated coda for the last two minutes, her five-octave voice punctuating her patented melismatic style. —Melissa Ruggieri, USA Today, 23 Sep. 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