incumbent

Definitions:

Lying or resting on, as a duty or obligation; indispensable; in bot, applied to cotyledons with the radicle on their back.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (adjective) (adj.) (adjective)
Lying or resting on; lying on, as a duty; said of the anthers of plants, when so disposed as to lie one over the other; said of the wings of insects, when one laps over the other.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (adjective) (adj.) (adjective)
The person in present possession of a benefice or of an office.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)
INCUMBENTLY.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (adverb) (adv.) (adverb)
One who holds an office.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (noun) (n.) (noun)
One who holds a benefice or office.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (noun) (n.) (noun)
Lying upon; bent downwards to lie along a base; cotyledons with hypocotyl applied to the back; hairs or spines applied lengthwise to their base.
- A dictionary of scientific terms. By Henderson, I. F.; Henderson, W. D. Published 1920. (adjective) (adj.) (adjective)
Lying on; resting on, as a duty.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (adjective) (adj.) (adjective)
Lying or resting on: lying on as a duty: indispensable.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (adjective) (adj.) (adjective)
The holder of an office; a clergyman in possession of a parish.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (noun) (n.) (noun)
The person who is in the possession of an office, as of an ecclesiastical benefice.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (noun) (n.) (noun)
Lying upon; imposed as a duty; obligatory.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (adjective) (adj.) (adjective)
One who holds an ecclesiastical benefice. ( in England or Ireland).
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (noun) (n.) (noun)

Usage examples:

When we are wondering how far it is our right and duty to interfere between a man and his house property or whether it is incumbent upon the nation to take upon itself the burden of housing its people, it is useful to look on these pictures of England in the glorious days of Queen Victoria and Albert the Great and Good.
- The Law and the Poor by Edward Abbott Parry
I have been the incumbent of this highly unpleasant office for two hundred years to- night."
- Humorous Ghost Stories by Dorothy Scarborough
That is too true; but many sober men and good Christians among them do hope, that in time there may be a reformation of those things; and I took the boldness to put the Queen and the present King in mind of the duty incumbent upon them in that business; and this I did with becoming freedom, and it was well taken.
- A Journal of the Swedish Embassy in the Years 1653 and 1654, Vol II. by Bulstrode Whitelocke