plaint vs United Kingdom of Great Britain and Northern Ireland

plaint and United Kingdom of Great Britain and Northern Ireland both are nouns.

Word	Noun	Adjective	Verb	Adverb
plaint	Yes	No	No	No
United Kingdom of Great Britain and Northern Ireland	Yes	No	No	No

plaint (noun)	United Kingdom of Great Britain and Northern Ireland (noun)
a cry of sorrow and grief	a monarchy in northwestern Europe occupying most of the British Isles; divided into England and Scotland and Wales and Northern Ireland; `Great Britain' is often used loosely to refer to the United Kingdom
(United Kingdom) a written statement of the grounds of complaint made to court of law asking for the grievance to be redressed