sestet

from WordNet (r) 3.0 (2006)
sestet
    n 1: the cardinal number that is the sum of five and one [syn:
         {six}, {6}, {VI}, {sixer}, {sise}, {Captain Hicks}, {half a
         dozen}, {sextet}, {sestet}, {sextuplet}, {hexad}]
    2: six performers or singers who perform together [syn:
       {sextet}, {sextette}, {sestet}]
    3: a set of six similar things considered as a unit [syn:
       {sextet}, {sextette}, {sestet}]
    4: a musical composition written for six performers [syn:
       {sextet}, {sextette}, {sestet}]
    5: a rhythmic group of six lines of verse
    
from The Collaborative International Dictionary of English v.0.48
Sestet \Ses*tet"\, n. [It. sestetto, fr. sesto sixth, L. sextus,
   fr. sex six.]
   1. (Mus.) A piece of music composed for six voices or six
      instruments; a sextet; -- called also {sestuor}. [Written
      also {sestett}, {sestette}.]
      [1913 Webster]

   2. (Poet.) The last six lines of a sonnet.
      [1913 Webster]
    

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