1. [n]  a vault or building where corpses or bones are deposited
2. [adj]  gruesomely indicative of death or the dead; "a charnel smell came from the chest filled with dead men's bones"; "ghastly shrieks"; "the sepulchral darkness of the catacombs"

CHARNEL is a 7 letter word that starts with C.

1. \Char"nel\, a. [F. charnel carnal, fleshly, fr. L.
   carnalis. See {Carnal}.]
   Containing the bodies of the dead. ``Charnel vaults.''
   --Milton.
   
   {Charnel house}, a tomb, vault, cemetery, or other place
      where the bones of the dead are deposited; originally, a
      place for the bones thrown up when digging new graves in
      old burial grounds.
   
   

2. \Char"nel\, n.
   A charnel house; a grave; a cemetery.
   
         In their proud charnel of Thermopyl[ae]. --Byron.