1. plural of octave; intervals of eight musical notes or the notes themselves that are eight steps apart in a musical scale
Usage: music theory
2. plural of octave; periods of eight days, especially in religious observances
Usage: religious; formal

Examples

• The pianist practiced scales across multiple octaves.
• Her voice could span nearly three octaves.
• The song modulates up two octaves in the chorus.
• Church bells rang for octaves following Easter.
• The composer wrote pieces covering four octaves on the keyboard.
• Musicians tune their instruments to match octaves precisely.