o·ver·lay 1 
(ō′vər-lā)
(ō′vər-lā)tr.v. o·ver·laid (-lād), o·ver·lay·ing, o·ver·lays
1. To lay or spread over or on.
2.
a. To cover the surface of with a decorative layer or design: overlay wood with silver.
b. To embellish superficially: a simple tune that was overlaid with ornate harmonies.
3. Printing To put an overlay on.
4. To create (a new area code) having the same boundaries as another: In Maryland, area code 240 was overlaid on top of area code 301.
n. (ōvər-lā′)
1. Something that is laid over or covers something else.
2. A layer of decoration, such as gold leaf or wood veneer, applied to a surface.
3. Printing A piece of paper used on a press tympan to vary the pressure that produces light and dark tones.
4. A transparent sheet containing graphic matter, such as labels or colored areas, placed on illustrative matter to be incorporated into it.
5. An area code whose boundaries are the same as another area code.