from
The Collaborative International Dictionary of English v.0.48
Octave \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.
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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.
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Note: The ratio of a musical tone to its octave above is 1:2
as regards the number of vibrations producing the
tones.
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3. (Poet.) The first two stanzas of a sonnet, consisting of
four verses each; a stanza of eight lines.
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With mournful melody it continued this octave. --Sir
P. Sidney.
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{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}.
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4. A small cask of wine, the eighth part of a pipe.
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