Representative

Do not abbreviate.

U.S. Congress:

            the House of Representatives, the House

            Representative Francis Downey, the representative, the congressman

            Congressman/Congresswoman is often used as a title in place of representative,

                        although technically it refers to any member of Congress.

state legislature:

             State Representative Bill Marr, Representative Bill Marr

             the state representative, the representative

             House of Delegates, the house