This is the 7192nd most frequent Polish word.
janina
"Janina" is a Polish feminine given name.
Here 'Janina' is used as a proper noun, specifically a first name referring to a person.
Janina mieszka w Warszawie.
Janina lives in Warsaw.
In this sentence, 'Janina' continues to be used as a proper noun and is in a grammatical form reflecting a direct object in the sentence.
Rozmawiałem dzisiaj z Janiną o projekcie.
I talked to Janina today about the project.
Here 'Janina' is part of a compound noun used to denote a specific place or entity, rather than referring to a person.