a feast day and the seven days following it
"The church announced that the entire octave of St. Jude would be celebrated as a time for special prayers and community gatherings."
a musical interval of eight tones
"The violinist soared through an octave, shifting from the lowest string to the highest in a single fluid motion."
a rhythmic group of eight lines of verse
"The poet structured her sonnet into two distinct octaves, each resolving a separate emotional conflict before moving to the tercets."
An interval of twelve semitones spanning eight degrees of the diatonic scale, representing a doubling or halving in pitch frequency.
"The violinist adjusted her tuning so that the high G formed a perfect octave above the cello's low C, ensuring their pitches doubled exactly in frequency."
Alternative form of octavate
"He was told that his rare musical instrument could be referred to as an octave, though he knew it was simply an alternative spelling for an octavate."
Consisting of eight; eight in number.
"The choir was organized into an octave, consisting of exactly eight members ranging from soprano to bass."