Pronunciation: (ok'tiv, -tāv),[key] —n. 1. Music. a. a tone on the eighth degree from a given tone.
b. the interval encompassed by such tones.
c. the harmonic combination of such tones.
d. a series of tones, or of keys of an instrument, extending through this interval.
2. a pipe-organ stop whose pipes give tones an octave above the normal pitch of the keys used.
3. a series or group of eight.
4. Also called octet.Pros. a. a group of eight lines of verse, esp. the first eight lines of a sonnet in the Italian form. Cf. sestet (def. 1).
b. a stanza of eight lines.
5. the eighth of a series.
6. Eccles. a. the eighth day from a feast day, counting the feast day as the first.
b. the period of eight days beginning with a feast day.
7. one eighth of a pipe of wine.
8. Fencing.the eighth of eight defensive positions.