This is the 6930th most frequent Polish word.
gliwice
Gliwice: A city in southern Poland, located in the Silesian Voivodeship.
In this sentence, 'Gliwice' is used as a proper noun, specifically the name of a city in Poland.
Odwiedziłem Gliwice w zeszłym tygodniu.
I visited Gliwice last week.
Here, 'Gliwickie' is an adjective derived from 'Gliwice', used to describe something related to the city of Gliwice, in this case, the horticultural fairs.
Gliwickie targi ogrodnicze są zawsze pełne ludzi.
The Gliwice horticultural fairs are always crowded.
In this case, 'Gliwice' is used as the subject of the sentence, serving again as a proper noun to refer directly to the city itself.