Buttonhole

A buttonhole is a reinforced hole in fabric that a button can pass through, allowing one piece of fabric to be secured to another. The raw edges of a buttonhole are usually finished with stitching. This may be done either by hand or by a sewing machine. Some forms of button, such as a frog, use a loop of cloth or rope instead of a buttonhole.^[1]

The term buttonhole can also refer to a flower worn in the lapel buttonhole of a coat or jacket, which is referred to simply as a "buttonhole" or "boutonnière".^[2]