hearth money vs Peter's pence

hearth money and Peter's pence both are nouns.

Word	Noun	Adjective	Verb	Adverb
hearth money	Yes	No	No	No
Peter's pence	Yes	No	No	No

As nouns, hearth money and Peter's pence are synonyms defined as:

hearth money and Peter's pence: an annual contribution made by Roman Catholics to support the papal see

hearth money (noun)	Peter's pence (noun)
an annual contribution made by Roman Catholics to support the papal see	an annual contribution made by Roman Catholics to support the papal see