This is the 9328th most frequent German word.
mateusz
The German word "Mateusz" is not a common German word; it is a Polish given name equivalent to "Matthew" in English.
In this sentence, "Mateusz" is a proper noun functioning as the name of an individual being described.
Mateusz ist ein wirklich netter Freund.
Mateusz is a really nice friend.
Here, the word "Mateusz" serves as a proper noun, the object of the verb "getroffen" (met).
Ich habe Mateusz gestern im Park getroffen.
I met Mateusz in the park yesterday.
In this context, "Mateusz" functions as the subject of the verb "liebt" (loves), referring to the person engaging in the action.