Wordnet 3.0
VERB (1)
1. 
 become or cause to become soft or liquid; 
- Example: "The sun melted the ice"- Example: "the ice thawed"- Example: "the ice cream melted"- Example: "The heat melted the wax"- Example: "The giant iceberg dissolved over the years during the global warming phase"- Example: "dethaw the meat"[syn: dissolve, thaw, unfreeze, unthaw, dethaw, melt]
WordNet (r) 3.0 (2006):
unthaw
    v 1: become or cause to become soft or liquid; "The sun melted
         the ice"; "the ice thawed"; "the ice cream melted"; "The
         heat melted the wax"; "The giant iceberg dissolved over the
         years during the global warming phase"; "dethaw the meat"
         [syn: dissolve, thaw, unfreeze, unthaw, dethaw,
         melt]