This is the 9348th most frequent German word.
mbappes
The term "mbappes" is not a German word. It may be a reference to the French footballer Kylian Mbappé.
In this sentence, 'Mbappé' is used to indicate possession, specifically referring to the jersey belonging to Mbappé.
Mbappés Trikot habe ich gestern im Sportgeschäft gesehen.
I saw Mbappé's jersey at the sports store yesterday.
Here, 'Mbappé' is used to describe an attribute (speed) associated with the football player named Mbappé.
Die Geschwindigkeit von Mbappé beeindruckt alle Fußballfans.
Mbappé's speed impresses all football fans.
In this case, 'Mbappé' is used as a proper noun identifying a person, specifically the football player who is the idol of the subject's friend.