Gradually soften what has melted (4)
I believe the answer is:
thaw
'gradually soften' is the definition.
'thaw' can be an answer for 'soften' (I've seen this in another clue). I'm not certain of the 'gradually' bit.
'what has melted' is the wordplay.
'what' can be anagrammed to 'THAW'.
But, I'm not sure how the anagram is indicated.
Can you help me to learn more?
(Other definitions for thaw that I've seen before include "detente" , "Unfreeze, defrost" , "when the temperature rises?" , "Become less stiff, more relaxed" , "Become warmer" .)