Frozen to the core? (4-7)
I believe the answer is:
cold-hearted
'frozen to the core?' is the definition.
I can't judge whether this definition defines the answer.
'frozen to the core?' is the wordplay.
'frozen' becomes 'cold' (associated in meaning).
'to the core?' becomes 'hearted' (I can't justify this - if you can you should believe this answer much more).
'cold'+'hearted'='COLD-HEARTED'
Can you help me to learn more?
(Other definitions for cold-hearted that I've seen before include "Indifferent" , "Unkind" , "Unfeeling" .)