This is the 2317th most frequent German word.
karlsruher
"Karlsruher" refers to something or someone from Karlsruhe, a city in Germany.
Here, 'Karlsruher' is used as an adjective to indicate that the castle is located in Karlsruhe.
Er besucht das Karlsruher Schloss jeden Sommer.
He visits the Karlsruhe Palace every summer.
In this sentence, 'Karlsruher' acts as an adjective to describe the team, identifying them as being from Karlsruhe.
Die Karlsruher Mannschaft hat das Spiel gewonnen.
The Karlsruhe team won the game.
Here, 'Karlsruher' functions as a nominalized adjective to represent someone who is a resident of Karlsruhe.