octave

An interval of twelve semitones spanning eight degrees of the diatonic scale, representing a doubling or halving in pitch frequency.

“The melody jumps up an octave at the beginning, then later drops back down an octave.”

The pitch an octave higher than a given pitch.

“The bass starts on a low E, and the tenor comes in on the octave.”

A coupler on an organ which allows the organist to sound the note an octave above the note of the key pressed (cf sub-octave)

A poetic stanza consisting of eight lines; usually used as one part of a sonnet.

The eighth defensive position, with the sword hand held at waist height, and the tip of the sword out straight at knee level.

The day that is one week after a feast day in the Latin rite of the Catholic Church.

An eight-day period beginning on a feast day in the Latin rite of the Catholic Church.

An octonion.

Any of a number of coherent-noise functions of differing frequency that are added together to form Perlin noise.

The subjective vibration of a planet.

Consisting of eight; eight in number.