Octave

ok′tāv, adj. eight: consisting of eight.— n. an eighth: that which consists of eight: the eighth day after a church festival, counting the feast-day itself as the first: the period between a festival and its octave: ( mus. ) an eighth, or an interval of twelve semitones: the eighth part of a pipe of wine. [Fr.,—L. octavus , eighth— octo , eight.]