As nouns the difference between primacy and firster
is that primacy is the state or condition of being prime or first, as in time, place, rank, etc., hence, excellency; supremacy while firster is a person who advocates the primacy of the named entity (who puts it first.
As an adjective firster is
earlier, former.
primacy
English
Noun
(-)
The state or condition of being prime or first, as in time, place, rank, etc., hence, excellency; supremacy.
The office, rank, or character of a primate; the chief ecclesiastical station or dignity in a national church; the office or dignity of an archbishop; as, the primacy of England.
firster
English
Noun
(
en noun)
(in combination) A person who advocates the primacy of the named entity (who puts it first)