Source : Webster's Revised Unabridged Dictionary (1913)

Felt grain \Felt grain\, the grain of timber which is transverse
   to the annular rings or plates; the direction of the
   medullary rays in oak and some other timber. --Knight. Felt
\Felt\, v. t. [imp. & p. p. {Felted}; p. pr. & vb. n.
   {Felting}.]
   1. To make into felt, or a feltike substance; to cause to
      adhere and mat together. --Sir M. Hale.

   2. To cover with, or as with, felt; as, to felt the cylinder
      of a steam emgine.