This is the 3448th most frequent German word.
kellner
Waiter.
Here, 'Kellner' functions as a noun referring to a male waiter who performs the act of serving food in a restaurant.
Der Kellner serviert uns das Abendessen.
The waiter is serving us dinner.
In this sentence, 'Kellner' is used nominatively as a career or job title, indicating the profession someone aims to pursue.
Ich möchte als Kellner arbeiten.
I want to work as a waiter.
Here, 'Kellner' is pluralized to 'Kellner' to refer to multiple people who work as waiters, showing its usage in describing a group.