A more thorough explanation:

Definition: An incumbent is a person who currently holds an official position, especially in politics.

Examples:

• The incumbent president is seeking re-election.
• The incumbent mayor has been in office for ten years.
• As the incumbent senator, she has a lot of experience in the legislative process.

The examples illustrate that an incumbent is someone who is currently holding a position of power or authority. In politics, an incumbent is often seeking re-election to continue their term in office. The length of time an incumbent has been in office can vary, as seen in the example of the mayor who has been in office for ten years. The example of the senator also shows that being an incumbent can provide experience and knowledge in a particular field or area of work.