NOUN (3)

1. a process that impregnates something with calcium (or calcium salts);

2. tissue hardened by deposition of lime salts;

3. an inflexible and unchanging state;
- Example: "the calcification of negotiations"

The Collaborative International Dictionary of English v.0.48:

Calcification \Cal`ci*fi*ca"tion\
   (k[a^]l`s[i^]*f[i^]*k[=a]"sh[u^]n), n. (Physiol.)
   The process of change into a stony or calcareous substance by
   the deposition of lime salt; -- normally, as in the formation
   of bone and of teeth; abnormally, as in calcareous
   degeneration of tissue.
   [1913 Webster]

WordNet (r) 3.0 (2006):

calcification
    n 1: a process that impregnates something with calcium (or
         calcium salts)
    2: tissue hardened by deposition of lime salts
    3: an inflexible and unchanging state; "the calcification of
       negotiations"