Charlie - Geordies are the lovable folk living along the area most Yanks would think of as the border between Scotland and England - The city of Newcastle Upon Tyne and its environs (Gateshead, etc.,) is an example of same.

(There are other descriptions, but I'm beiing polite.)

Hence, a Geordie-ism is a delightful colloqial expression of language variant spoken by those same lovable folk. As one Scouser I know comments, "Any resemblance between Geordie and English is entirely by chance."

Have a day.

Pete