a.

1. 负有职责的，义不容辞的[F][（+on/upon）]
   It's incumbent on you to warn them.

   你有责任告诫他们。

   It is incumbent upon you to tell the truth.

   你有义务说出真相。

2. 现任的，在职的[B]
   the incumbent president

   现任总统

   The incumbent General Manager is my brother.

   目前在职的总经理是我的弟弟。

3. 压在上面的；倚靠的[（+on/upon）]

n.[C]

1. 现任者，在职者
   He, as the incumbent, is vulnerable on this.

   作为在职者，他在这个问题上易受攻击。

2. 【英】教区牧师；领圣俸者

adj.

1. (incumbent on/upon) necessary for (someone) as a duty or responsibility.
2. (of an official or regime) currently holding office.

n.