Noah Webster's New International Dictionary of the English Language

1. (a.) Lying; resting; reclining; recumbent; superimposed; superincumbent.

2. (a.) Lying, resting, or imposed, as a duty or obligation; obligatory; always with on or upon.

3. (a.) Leaning or resting; -- said of anthers when lying on the inner side of the filament, or of cotyledons when the radical lies against the back of one of them.

4. (a.) Bent downwards so that the ends touch, or rest on, something else; as, the incumbent toe of a bird.

5. (n.) A person who is in present possession of a benefice or of any office.