Source : Webster's Revised Unabridged Dictionary (1913)

Overlay \O`ver*lay"\, v. t. [imp. & p. p. {Overlaid}; p. pr. &
   vb. n. {Overlaying}.]
   1. To lay, or spread, something over or across; hence, to
      cover; to overwhelm; to press excessively upon.

            When any country is overlaid by the multitude which
            live upon it.                         --Sir W.
                                                  Raleigh.

            As when a cloud his beams doth overlay. --Spenser.

            Framed of cedar overlaid with gold.   --Milton.

            And overlay With this portentous bridge the dark
            abyss.                                --Milton.

   2. To smother with a close covering, or by lying upon.

            This woman's child died in the night; because she
            overlaid it.                          --1 Kings iii.
                                                  19.

            A heap of ashes that o'erlays your fire. --Dryden.

   3. (Printing) To put an overlay on.

Overlaying \O"ver*lay"ing\, n.
   A superficial covering; a coating.