Meaning : In a sincere and heartfelt manner.
Example :
I would dearly love to know.
Synonyms : in a heartfelt way
Meaning : At a great cost.
Example :
He paid dearly for the food.
This cost him dear.
Synonyms : dear
Meaning : With affection.
Example :
She loved him dearly.
He treats her affectionately.
Synonyms : affectionately, dear