Definition of: overlay

(ō′vər·lā′) noun
1. Printing A piece of paper placed on the tympan of a press to make the impression heavier at the corresponding part of the form, or to compensate for a depression in the form.
2. Anything that overlies, covers, or partly covers something.
3. Ornamental work overlaid on wood, as with veneers, etc.
4. A sheet of transparent material carrying information of a special or confidential nature to supplement the details of the map on which it is laid.
5. Scot. A cravat.
—v.t. (ō′vər·lā′) ·laid, ·lay·ing
1. To spread something over, as with a decorative pattern or layer.
2. To lay or place over or upon something else.
3. Printing To put an overlay upon.
4. To overburden; weigh down.