Noun - An applique is a decorative motif stitched onto a garment or other item. These can be of any size and of any fabric or material that can be sewn.
Verb - To applique is to sew a decorative motif onto a garment or other item.
These are sometimes used by vintage sellers to cover holes, which is fine as long as the seller tells the buyer they have done this.
Nana Pants With Lace Applique covering a hole