First person Gregory takes to heart (3)
I believe the answer is:
ego
'to heart' is the definition.
(thesaurus)
'first person gregory' is the wordplay.
'EGO' is hidden within the letters.
However, I am not sure how this is indicated.
'takes' is the link.
Can you help me to learn more?
(Other definitions for ego that I've seen before include "Sense of self, conceit" , "number one" , "Self-confidence" , "(Self-assertive) personality" , "One's sense of self-importance" .)