VERB (4)

1. become impregnated with calcium salts;

2. become inflexible and unchanging;
- Example: "Old folks can calcify"

3. turn into lime; become calcified;
- Example: "The rock calcified over the centuries"

4. convert into lime;
- Example: "the salts calcified the rock"

The Collaborative International Dictionary of English v.0.48:

Calcify \Cal"ci*fy\ (k[a^]l"s[i^]*f[imac]), v. t. [imp. & p. p.
   Calcified (-f[imac]d); p. pr. & vb. n. Calcifying.] [L.
   calx, calcis, lime + -fy.]
   To make stony or calcareous by the deposit or secretion of
   salts of lime.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Calcify \Cal"ci*fy\, v. i.
   To become changed into a stony or calcareous condition, in
   which lime is a principal ingredient, as in the formation of
   teeth.
   [1913 Webster]

WordNet (r) 3.0 (2006):

calcify
    v 1: become impregnated with calcium salts [ant: decalcify]
    2: become inflexible and unchanging; "Old folks can calcify"
    3: turn into lime; become calcified; "The rock calcified over
       the centuries"
    4: convert into lime; "the salts calcified the rock"