Stationary

Definition:

(a.) Not moving; not appearing to move; stable; fixed.
(a.) Not improving or getting worse; not growing wiser, greater, better, more excellent, or the contrary.
(a.) Appearing to be at rest, because moving in the line of vision; not progressive or retrograde, as a planet.
(n.) One who, or that which, is stationary, as a planet when apparently it has neither progressive nor retrograde motion.

Compare stationary with other words:

stationary vs. steady