The word "bellybutton" is a common term used to describe the small indentation or scar on the abdomen that marks the site of the umbilical cord. However, there are several other synonyms that are used interchangeably for this anatomical feature. Some of the common terms used include navel, umbilicus, tummy button, belly button, or simply just "the button." Other more informal terms include the "innie" or "outie," depending on the protrusion of the bellybutton. These different terms are used depending on context, preference, or familiarity and serve as an alternative way of describing the same unique feature of the body.