This is the 15605th most frequent Polish word.
studencką
"Studencką" is the accusative or instrumental singular form of "studencka," meaning "student" or "related to students" (feminine adjective).
The word "studencką" is an adjective in the accusative singular form which qualifies "bibliotekę" (library), meaning that the library is primarily intended for students.
Odwiedziłem bibliotekę studencką.
I visited the student library.
Here, "studencką" modifies "ofertę" (offer) as an adjective, indicating that the offer is related to housing options for students.
Wybrałem studencką ofertę mieszkaniową.
I chose the student housing offer.
In this sentence, "studencką" works adjectivally, enhancing "kawiarnią" (cafe) to specify that the cafe caters to students.