v (intransitive|of a person) To be in a position in which the upper body is upright and the legs (especially the upper legs) are supported by some object.
v (intransitive|of a person) To move oneself into such a position.
v (intransitive|of an object) To occupy a given position permanently.
v (government) To be a member of a deliberative body.
v (legal|government) Of a legislative or, especially, a judicial body such as a court, to be in session.
v (intransitive|of an agreement or arrangement) To be accepted or acceptable; to work.