(Oc`ta*roon") n. See Octoroon.
(Oc"ta*style) a. See Octostyle.
(Oc"ta*teuch) n. [L. octateuchus, Gr. .] A collection of eight books; especially, the first eight
books of the Old Testament. [R.]
(Oc*tav"a*lent) a. [Octa- + L. valens, p. pr. See Valence.] (Chem.) Having a valence of
eight; capable of being combined with, exchanged for, or compared with, eight atoms of hydrogen; said
of certain atoms or radicals.
(Oc"tave) n. [F., fr. L. octava an eighth, fr. octavus eighth, fr. octo eight. See Eight, and cf.
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
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.
(Oc"tave) a. Consisting of eight; eight. Dryden.
(Oc*ta"vo) n.;pl. Octavos [L. in octavo; in in + octavo, abl. of octavus. See Octave.] A
book composed of sheets each of which is folded into eight leaves; hence, indicating more or less definitely
a size of book so made; usually written 8vo or 8°.
(Oc*ta"vo), a. Having eight leaves to a sheet; as, an octavo form, book, leaf, size, etc.
(Oc"tene) n. [See Octo-.] (Chem.) Same as Octylene.
(Oc*ten"ni*al) a. [L. octennium a period of eight years; octo eight + annus year.] Happening
every eighth year; also, lasting a period of eight years. Johnson. Oc*ten"ni*al*ly, adv.
(Oc*tet") n. [From L. octo eight, like E. duet, fr.L. duo. See Octave.] (Mus.) A composition for
eight parts, usually for eight solo instruments or voices.
(Oc"tic) a. [Octo- + - ic.] (Math.) Of the eighth degree or order. n. (Alg.) A quantic of the
(Oc"tile) n. [Cf. F. octil, a. See Octant.] Same as Octant, 2. [R.]
(Oc*til"lion) n. [L. octo eight + -illion, as in E. million: cf. F. octillion.] According to the French
method of numeration (which method is followed also in the United States) the number expressed by a
unit with twenty-seven ciphers annexed. According to the English method, the number expressed by a
unit with forty-eight ciphers annexed. See Numeration.