The Collaborative International Dictionary of English v.0.48:

Indurate \In"du*rate\, v. t. [imp. & p. p. Indurated; p. pr. &
   vb. n. Indurating.]
   [1913 Webster]
   1. To make hard; as, extreme heat indurates clay; some
      fossils are indurated by exposure to the air.
      [1913 Webster]

   2. To make unfeeling; to deprive of sensibility; to render
      obdurate.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Indurated \In"du*ra`ted\, a.
   Hardened; as, indurated clay; an indurated heart.
   --Goldsmith.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "indurated":
   Philistine, backed, brazen, calcified, callous, calloused,
   case-hardened, conscienceless, crusted, crusty, crystallized,
   flinty, fossilized, granulated, hard, hardened, hardhearted,
   heartless, hornified, impervious, incrusted, indurate, insensitive,
   inured, lapidified, lost to shame, obdurate, ossified,
   pachydermatous, petrified, proof against, reinforced, rigidified,
   sclerotic, seared, set, shameless, solidified, steeled,
   steeled against, steely, stiffened, stony, strengthened,
   thick-skinned, toughened, unblushing, vitrified