[adj] relating to or having the symptoms of cachexia
 
CACHECTIC is a 9 letter word that starts with C.
Webster's 1913 Dictionary
Definition:
\Ca*chec"tic\, Cachectical \Ca*chec"tic*al\, a. [L.
cachecticus, Gr. ?????????: cf. F. cachectique.]
Having, or pertaining to, cachexia; as, cachectic remedies;
cachectical blood. --Arbuthnot.