Quiescent

Part of speech: noun (n.)

A silent letter. M. Stuart.

Part of speech: adjective (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."