Definition of octave

• n. - The eighth day after a church festival, the festival day being included; also, the week following a church festival.
• n. - 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.
• n. - The whole diatonic scale itself.
• n. - The first two stanzas of a sonnet, consisting of four verses each; a stanza of eight lines.
• n. - A small cask of wine, the eighth part of a pipe.
• a. - Consisting of eight; eight.