President-elect
Though an outgoing President of Ireland who has been re-elected is usually described in the media as "president" before the taking of the Declaration of Office, that is actually incorrect. The Irish Constitution makes it clear that a president's term of office expires on the day before the inauguration of their successor. In the interregnum period, the Presidential Commission acts as president, through given that it is usually for less than 11 hours no Presidential Commission has ever been called on to do anything in that period. Technically for that period the outgoing president is a former president and, if re-elected, President-elect.
Read more about this topic: Presidential Inauguration (Ireland)