1. [adj]  causing no symptoms; "a quiescent tumor"
2. [adj]  being quiet or still or inactive
3. [adj]  not active or activated; "the quiescent level of centimeter wave-length solar radiation"
4. [adj]  marked by a state of tranquil repose; "the quiescent melancholy of the town"

QUIESCENT is a 9 letter word that starts with Q.

1. \Qui*es"cent\, a. [L. quiescens, -entis, p. pr. of
   quiescere: cf. F. quiescent. See {Quiesce}.]
   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. (Gram.) Not sounded; silent; as, y is quiescent in ``day''
      and ``say.''
   
   

2. \Qui*es"cent\, n. (Gram.)
   A silent letter. --M. Stuart.