Why is it der Wiesbadener?

Wiesbadener ends in -er, and most nouns ending in -er are masculine: in a German dictionary, 86% of them take der.

All nouns ending in -er
Sense 1
der

Meaning

[1] belonging to Wiesbaden, regarding Wiesbaden, from Wiesbaden

[1] zu Wiesbaden gehörend, Wiesbaden betreffend, aus Wiesbaden stammend

Examples

[1] "He likes to drive expensive cars, sometimes had a Jaguar and regularly diet with his wife in Wiesbaden's luxury restaurant" "

[1] „Er fährt gerne teure Autos, hatte auch mal einen Jaguar und speist mit seiner Frau regelmäßig in Wiesbadener Luxusrestaurants.“

Declension

Positiv Komparativ Superlativ
Wiesbadener — —

Pronunciation

Dictionary entries include material from Wiktionary. Wiktionary