This is the 4125th most frequent German word.
amtierenden
"Amtierenden" means "incumbent" or "currently holding office."
In this sentence, 'amtierenden' is used as an adjective modifying 'Präsident', signifying that the person currently holds the position of president.
Der amtierende Präsident besuchte die Stadt.
The incumbent president visited the city.
Here, 'amtierenden' is an adjective describing 'Regierung', indicating that the government is presently in power.
Wir diskutierten über die amtierende Regierung.
We discussed the incumbent government.
In this context, 'amtierenden' modifies 'Meister', referring to someone who currently holds the title of champion.