incumbent incumbent /ˌɪnˈkʌmbənt/

adjective

1. Currently holding an office  ( incumbent )
   currently holding an office
    The incumbent governor
   the incumbent governor
   
2. Necessary (for someone) as a duty or responsibility; morally binding  ( incumbent )
   necessary (for someone) as a duty or responsibility; morally binding
    It is incumbent on them to pay their own debts
   it is incumbent on them to pay their own debts
   
3. (geology) lying or leaning on something else  ( incumbent )
   (geology) lying or leaning on something else
    An incumbent geological formation
   an incumbent geological formation
   

noun

1. The official who holds an office  ( incumbent , officeholder )
   the official who holds an office