CLARY is a 5 letter word that starts with C.

1. \Clar"y\, v. i. [Cf. {Clarion}.]
   To make a loud or shrill noise. [Obs.] --Golding.
   
   

2. \Cla"ry\, n. [Cf. LL. sclarea, scarlea, D. & G. scharlei,
   F. sclar['e]e.] (Bot.)
   A plant ({Salvia sclarea}) of the Sage family, used in
   flavoring soups.
   
   {Clary water}, a composition of clary flowers with brandy,
      etc., formerly used as a cardiac.