Quiescent /(?)/

Qui·es·cent

Quiescent

a.
  1. Being in a state of repose; at rest; still; not moving; as, a quiescent body or fluid.
  2. Not ruffed with passion; unagitated; not in action; not excited; quiet; dormant; resting.
    In times of national security, the feeling of patriotism . . . is so quiescent that it seems hardly to exist.
    — Prof. Wilson.
  3. Not sounded; silent; as, y is quiescent in “day” and “say.” (Gram.)

Quiescent

n.
  1. A silent letter. (Gram.)