"Overlaid" refers to the act of covering something entirely or excessively. The opposite of the word "overlaid" is to "uncover" or to "reveal." It means to expose something or remove any layer of cover or concealment. Another antonym of "overlaid" is "unencumbered," which describes something that is not burdened or weighed down by additional layers or obstacles. Another antonym can be "uncovered," which refers to something that is not hidden or obscured in any way. Lastly, "unveiled" can also be an antonym for "overlaid," which implies that something has been revealed or made known after being previously hidden or covered.