n.1. The act or position of one that sits.
2. A period during which one is seated and occupied with a single activity, such as posing for a portrait or reading a book.
3. A session or term, as of a legislature or court.
4. a. An act, condition, or period of brooding on eggs by a bird; incubation.
b. The number of eggs under a brooding bird; a clutch.
adj.1. Incubating a nest of eggs: a sitting hen.
2. Occupying an official position; incumbent.
3. a. Of or for sitting: a sitting posture; a sitting area in a bus station.
b. Done or executed while sitting.