Source : Webster's Revised Unabridged Dictionary (1913)

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.

   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.

   Note: 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.

Octave \Oc"tave\, a.
   Consisting of eight; eight. --Dryden.

Source : WordNet®

octave
     n 1: a feast day and the seven days following it
     2: a musical interval of eight tones [syn: {musical octave}]
     3: a rhythmic group of eight lines of verse

Source : Free On-Line Dictionary of Computing

Octave
     
         A high-level {interactive} language by John
        W. Eaton, with help from many others, like {MATLAB}, primarily
        intended for numerical computations.  Octave provides a
        convenient {command line interface} for solving linear and
        nonlinear problems numerically.
     
        Octave can do arithmetic for {real} and {complex} {scalars}
        and {matrices}, solve sets of nonlinear algebraic equations,
        integrate functions over finite and infinite intervals, and
        integrate systems of ordinary differential and
        differential-algebraic equations.
     
        Octave has been compiled and tested with {g++} and libg++ on a
        {SPARCstation 2} running {SunOS} 4.1.2, an {IBM} {RS/6000}
        running {AIX} 3.2.5, {DEC Alpha} systems running {OSF}/1 1.3
        and 3.0, a {DECstation 5000}/240 running {Ultrix} 4.2a, and
        {Intel 486} systems running {Linux}.  It should work on most
        other {Unix} systems with {g++} and libg++.
     
        Octave is distributed under the {GNU} {General Public
        License}.  It requires {gnuplot}, a {C++} compiler and
        {Fortran} compiler or {f2c} translator.
     
        Latest version: 2.0.16 (released 2000-01-30), as of 2000-06-26.
     
        {home (http://www.che.wisc.edu/octave)}.
     
        {(ftp://ftp.che.wisc.edu/pub/octave/)} or your nearest {GNU
        archive site}.
     
        E-mail: .
     
        (2000-06-27)