The Collaborative International Dictionary of English v.0.48:

Lay \Lay\, a. [F. lai, L. laicus, Gr. ? of or from the people,
   lay, from ?, ?, people. Cf. Laic.]
   1. Of or pertaining to the laity, as distinct from the
      clergy; as, a lay person; a lay preacher; a lay brother.
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   2. Not educated or cultivated; ignorant. [Obs.]
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   3. Not belonging to, or emanating from, a particular
      profession; unprofessional; as, a lay opinion regarding
      the nature of a disease.
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   Lay baptism (Eccl.), baptism administered by a lay person.
      --F. G. Lee.

   Lay brother (R. C. Ch.), one received into a convent of
      monks under the three vows, but not in holy orders.

   Lay clerk (Eccl.), a layman who leads the responses of the
      congregation, etc., in the church service. --Hook.

   Lay days (Com.), time allowed in a charter party for taking
      in and discharging cargo. --McElrath.

   Lay elder. See 2d Elder, 3, note.
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