stagnant

adjective

Not flowing or moving, and often foul-smelling or stale.

adjective

Showing little or no activity or vitality; inactive or sluggish.

adjective

That stagnates; not flowing; not running in a current or steam; motionless; hence, impure or foul from want of motion

adjective

Not active or brisk; dull.

adjective

Lacking freshness, motion, flow, progress, or change; stale; motionless; still.

adjective

not growing or changing; without force or vitality

adjective

not circulating or flowing