noun a silent letter.
2. quiescent ·adj not sounded; silent; as, y is quiescent in "day" and "say.".
3. quiescent ·adj being in a state of repose; at rest; still; not moving; as, a quiescent body or fluid.
4. quiescent ·adj not ruffed with passion; unagitated; not in action; not excited; quiet; dormant; resting.