Wordnet 3.0
NOUN (2)
1. 
 a metal blade with a handle; 
 used as cutlery; 
2. 
 a knife with a fixed blade that is carried in a sheath; 
[syn: case knife, sheath knife]
The Collaborative International Dictionary of English v.0.48:
Case knife \Case" knife`\
   1. A knife carried in a sheath or case. --Addison.
      [1913 Webster]
   2. A large table knife; -- so called from being formerly kept
      in a case.
      [1913 Webster]
WordNet (r) 3.0 (2006):
case knife
    n 1: a metal blade with a handle; used as cutlery
    2: a knife with a fixed blade that is carried in a sheath [syn:
       case knife, sheath knife]