Source : Webster's Revised Unabridged Dictionary (1913)

Lawm \Lawm\, n. [Earlier laune lynen, i. e., lawn linen; prob.
   from the town Laon in France.]
   A very fine linen (or sometimes cotton) fabric with a rather
   open texture. Lawn is used for the sleeves of a bishop's
   official dress in the English Church, and, figuratively,
   stands for the office itself.

         A saint in crape is twice in lawn.       --Pope.