incumbent
US /ɪnˈkʌm.bənt/
UK /ɪnˈkʌm.bənt/

1.
现任的, 在职的
currently holding an office or position
:
•
The incumbent president is seeking re-election.
现任总统正在寻求连任。
•
The incumbent senator has served for two terms.
现任参议员已任职两届。
1.
现任者, 在职者
the holder of an office or post
:
•
The new candidate is challenging the incumbent.
新候选人正在挑战现任者。
•
It's difficult to unseat an incumbent with a strong record.
要罢免一位政绩卓著的现任者是很困难的。