The Collaborative International Dictionary of English v.0.48:

Skein \Skein\, n. [OE. skeyne, OF. escaigne, F. ['e]cagne,
   probably of Celtic origin; cf. Ir. sgainne, Gael. sgeinnidh
   thread, small twine; or perhaps the English word is
   immediately from Celtic.]
   1. A quantity of yarn, thread, or the like, put up together,
      after it is taken from the reel, -- usually tied in a sort
      of knot.
      [1913 Webster]

   Note: A skein of cotton yarn is formed by eighty turns of the
         thread round a fifty-four inch reel.
         [1913 Webster]

   2. (Wagon Making) A metallic strengthening band or thimble on
      the wooden arm of an axle. --Knight.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Skein \Skein\, n. (Zool.)
   A flight of wild fowl (wild geese or the like). [Prov. Eng.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

skein
    n 1: coils of worsted yarn

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "skein":
   animal fiber, artificial fiber, bevy, capillament, charm, cilium,
   cirrus, cloud, cobweb, covey, denier, fiber, fibrilla, filament,
   filamentule, flagellum, flight, flock, gaggle, gossamer, hair,
   hank, hive, jungle, knot, labyrinth, mesh, morass, murmuration,
   plague, snarl, spring, strand, suture, swarm, tangle, tendril,
   thread, threadlet, watch, web