overlay

transitive verb overlaid, overlaying

1. to lay or spread over
2. to cover or overspread, as with a decorative layer of something
3. Printing to place an overlay upon

noun

1. anything laid over another thing; covering
2. a decorative layer or the like, applied in overlaying
3. a transparent flap showing additional details, areas of color, etc. placed over a map, art work, etc.
4. ☆ in betting, odds which are set higher than expected or warranted
5. Printing the paper affixed to the impression surface of a press to help make a uniform impression