Source : Webster's Revised Unabridged Dictionary (1913)

Septet \Sep*tet"\, Septette \Sep*tette"\, n. [From L. septem
   seven, like duet, from L. duo.]
   1. A set of seven persons or objects; as, a septet of
      singers.

   2. (Mus.) A musical composition for seven instruments or
      seven voices; -- called also {septuor}.

Source : WordNet®

septet
     n 1: the cardinal number that is the sum of six and one [syn: {seven},
           {7}, {VII}, {sevener}, {heptad}]
     2: seven performers or singers who perform together [syn: {septette}]
     3: a set of seven similar things considered as a unit [syn: {septette}]
     4: seven people considered as a unit [syn: {septette}, {sevensome}]
     5: a musical composition written for seven performers [syn: {septette}]