Brno vs Brunn

Brno and Brunn both are nouns.

Word	Noun	Adjective	Verb	Adverb
Brno	Yes	No	No	No
Brunn	Yes	No	No	No

As nouns, Brno and Brunn are synonyms defined as:

Brno and Brunn: an industrial city in Moravia in Czech Republic to the southeast of Prague

Brno (noun)	Brunn (noun)
an industrial city in Moravia in Czech Republic to the southeast of Prague	an industrial city in Moravia in Czech Republic to the southeast of Prague