D defs.my
Entry 2 senses Webster, 1913

octet

/äk-tĕt'/ · oc·tet · IPA /ɒkˈtɛt/
01 n. A composition for eight parts, usually for eight solo instruments or voices.
  1. 1.
    A composition for eight parts, usually for eight solo instruments or voices.(Mus.)
  2. 2.
    A group of eight singers or eight musicians.