thirteensome

From thirteen +‎ -some.

thirteensome (plural thirteensomes)

1. (rare) A group of thirteen people or things.
   • 1916, Musical Courier and Review of Recorded Music‎^[1], volume 73, page 24:

     Their search through the musical archives of our folk literature has brought to light a “Hawaiian Serf Surf Song,” which they are arranging for a “thirteensome” made up of eleven ukuleles, one mixed voice and a snare drum.

   • 1986, Jerry Greene, “A Young McMahon waits his turn”, in The Orlando Sentinel, (November 9, 1986), p. C-11:

     Sometimes Jim and I would play golf together as part of a thirteensome. Jim would get about 13 guys together, all hitting balls on the same hole at the same time.

   • 2009, Razorcake, RoseDog Books, →ISBN, page 30:

     So if you have an eightsome, it should be five girls and three guys. A thirteensome should be eight girls and five guys.

   • 2012, James Ashton, Le Town Empire, iUniverse, →ISBN, page 173:

     And watch as Loki tried his damnednest to orchestrate a threesome, foursome, possibly thirteensome with his so-called supermodel [...]