What is "rag wool"

Rag \Rag\, n. [OE. ragge, probably of Scand, origin; cf. Icel. r["o]gg a tuft, shagginess, Sw. ragg rough hair. Cf. Rug, n.]

1. A piece of cloth torn off; a tattered piece of cloth; a shred; a tatter; a fragment.

   Cowls, hoods, and habits, with their wearers, tossed, And fluttered into rags.
   --Milton.

   Not having otherwise any rag of legality to cover the shame of their cruelty.
   --Fuller.

2. pl. Hence, mean or tattered attire; worn-out dress.

   And virtue, though in rags, will keep me warm.
   --Dryden.

3. A shabby, beggarly fellow; a ragamuffin.

   The other zealous rag is the compositor.
   --B. Jonson.

   Upon the proclamation, they all came in, both tag and rag.
   --Spenser.

4. (Geol.) A coarse kind of rock, somewhat cellular in texture.

5. (Metal Working) A ragged edge.

6. A sail, or any piece of canvas. [Nautical Slang] Our ship was a clipper with every rag set. --Lowell. Rag bolt, an iron pin with barbs on its shank to retain it in place. Rag carpet, a carpet of which the weft consists of narrow strips of cloth sewed together, end to end. Rag dust, fine particles of ground-up rags, used in making papier-mach['e] and wall papers. Rag wheel.

   1. A chain wheel; a sprocket wheel.

   2. A polishing wheel made of disks of cloth clamped together on a mandrel.

      Rag wool, wool obtained by tearing woolen rags into fine bits, shoddy.