The Collaborative International Dictionary of English v.0.48:

Layman \Lay"man\n.; pl. Laymen. [Lay, adj. + man.]
   1. One of the people, in distinction from the clergy; one of
      the laity; sometimes, a man not belonging to some
      particular profession, in distinction from those who do.
      [1913 Webster]

            Being a layman, I ought not to have concerned myself
            with speculations which belong to the profession.
                                                  --Dryden.
      [1913 Webster]

   2. A lay figure. See under Lay, n. (above). --Dryden
      [1913 Webster]

WordNet (r) 3.0 (2006):

layman
    n 1: someone who is not a clergyman or a professional person
         [syn: layman, layperson, secular] [ant: clergyman,
         man of the cloth, reverend]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

LAYMAN, eccl. law. One who is not an ecclesiastic nor a clergyman.