thaw
verb
- (of ice, snow, or another frozen substance, such as food) become liquid or soft as a result of warming.
John's favorite time during his month's stay in Antarctica was when the ice began to thaw and the penguins played around his cabin.
Nixon fostered better relations with Brezhnev because he felt that a thaw in the hostility between the US and Russia would be better for both countries and the world.