The Collaborative International Dictionary of English v.0.48:

Clot \Clot\, v. i. [imp. & p. p. Clotted; p. pr. & vb. n.
   Clotting.]
   To concrete, coagulate, or thicken, as soft or fluid matter
   by evaporation; to become a cot or clod.
   [1913 Webster]

WordNet (r) 3.0 (2006):

clotting
    n 1: the process of forming semisolid lumps in a liquid [syn:
         curdling, clotting, coagulation]