Wordnet 3.0
VERB (2)
1. 
 undergo decrepitation and crackle; 
- Example: "The salt decrepitated"2. 
 to roast or calcine so as to cause to crackle or until crackling stops; 
- Example: "decrepitate salts"
The Collaborative International Dictionary of English v.0.48:
Decrepitate \De*crep"i*tate\, v. t. [imp. & p. p.
   Decrepitated; p. pr. & vb. n. Decrepitating.] [Cf. F.
   d['e]cr['e]piter.]
   To roast or calcine so as to cause a crackling noise; as, to
   decrepitate salt.
   [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Decrepitate \De*crep"i*tate\, v. i.
   To crackle, as salt in roasting.
   [1913 Webster]
WordNet (r) 3.0 (2006):
decrepitate
    v 1: undergo decrepitation and crackle; "The salt decrepitated"
    2: to roast or calcine so as to cause to crackle or until
       crackling stops; "decrepitate salts"