Oc″tave (?), n. [F., fr. L. octava an eighth, fr. octavus eighth, fr. octo eight. See Eight, and cf. Octavo, Utas.] 1. The eighth day after a church festival, the festival day being included; also, the week following a church festival. “The octaves of Easter.” Jer. Taylor.
2. (Mus.) (a) The eighth tone in the scale; the interval between one and eight of the scale, or any interval of equal length; an interval of five tones and two semitones. (b) The whole diatonic scale itself.
☞ The ratio of a musical tone to its octave above is 1:2 as regards the number of vibrations producing the tones.
3. (Poet.) The first two stanzas of a sonnet, consisting of four verses each; a stanza of eight lines.
With mournful melody it continued this octave. Sir P. Sidney.
Double octave. (Mus.) See under Double. — Octave flute(Mus.), a small flute, the tones of which range an octave higher than those of the German or ordinary flute; — called also piccolo. See Piccolo.
4. A small cask of wine, the eighth part of a pipe.