Hide a broken heart (5)
I believe the answer is:
'hide' is the definition.
(I know that earth is a type of hide)
'a broken heart' is the wordplay.
'a broken' indicates an anagram.
'heart' anagrammed gives 'EARTH'.
(Other definitions for earth that I've seen before include "Make electrics safe" , "our present abode" , "electrical safety precaution" , "underground shelter" , "Third rock from the Sun" .)