America had always had a tendency to push westward, often spilling across even well-defined borders.

Surrounded by water on three sides and protected by high mountains along its eastern border, the country generally has well-defined natural borders.

"A benign lump usually has well-defined, clear borders that are not irregular."

There is no well-defined border between pre-machining and fine grinding.

Three other functional areas with well-defined borders appear on the other sides of the square.

Mason has crossed the well-defined border of a coach who believes you're either in or out.

A mass (lump) with a smooth, well-defined border is often benign.

This tumor grows relatively slowly and usually does not have well-defined borders.

Without well-defined borders, incidents between Russian and Japanese settlers began to occur.

Lesions are usually smooth, shiny, and red with well-defined borders.