Britisher vs patrial

Britisher and patrial both are nouns.

Word	Noun	Adjective	Verb	Adverb
Britisher	Yes	No	No	No
patrial	Yes	No	No	No

As nouns, patrial is a hyponym of Britisher; that is, patrial is a word with a more specific, narrower meaning than Britisher:

Britisher: a native or inhabitant of Great Britain
patrial: a person who has the right to be considered legally a British citizen (by virtue of the birth of a parent or grandparent)

Other hyponyms of Britisher include English person.

Britisher (noun)	patrial (noun)
a native or inhabitant of Great Britain	a person who has the right to be considered legally a British citizen (by virtue of the birth of a parent or grandparent)