overlay
n. countablen. something that you put on top of something else to cover it or add a new layer. It is often used to describe digital images or maps where one layer sits over another.
n. a layer of something that is placed over another surface for protection, decoration, or to provide additional information. In digital contexts, it refers to a graphical or data layer superimposed on a primary interface or image.
The map has a transparent overlay showing the new bus routes.
The software allows users to add a text overlay to their videos before sharing them online.
By applying a digital overlay of historical property boundaries onto the modern satellite imagery, researchers were able to identify the exact location of the original settlement.
From Middle English overleyen, from Old English oferleċġan, from Proto-West Germanic obarlaggjan, from Proto-Germanic uberlagjaną, equivalent to over- + lay. Cognate with Saterland Frisian uurläze, úurlääse, Dutch overleggen, German Low German overleggen, överleggen, German überlegen, Swedish överlägga, Norwegian overlegge. Compare overlie.
Often used with the preposition 'of' to describe the material or content of the layer.