MB vs United Kingdom of Great Britain and Northern Ireland

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

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

MB (noun)	United Kingdom of Great Britain and Northern Ireland (noun)
(a British degree) a bachelor's degree in medicine	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
a unit of information equal to 1024 kibibytes or 2^20 (1,048,576) bytes
a unit of information equal to 1000 kilobytes or 10^6 (1,000,000) bytes