What is Outgoing Politician?

Legal Definition
An outgoing politician is an elected or appointed politician that is serving at some point between the time of the election or appointment of his or her successor and the inauguration or date by which the successor assumes power. For heads of state, the terms used are outgoing president and outgoing prime minister, among others.

In many countries, toward the facilitation of a smooth transition, an outgoing president accepts advice from and consults with the president-elect. The term lame duck is often ascribed to an outgoing elected official in view of his relative impotence and impending exit from office, especially where his political party has lost control of a legislative or executive branch.
-- Wikipedia