This is the 9338th most frequent German word.
maulburgern
"Maulburgern" is a German slang term meaning to half-heartedly grumble or complain without taking any real action.
Here, 'maulburgern' is used to describe making mumbling sounds during eating.
Die Kinder mussten aufhören, beim Essen zu maulburgern.
The children had to stop mumbling while eating.
In this context, 'maulburgern' refers to murmuring or complaining quietly.
Er maulburgert immer, wenn ihm die Hausaufgaben schwer erscheinen.
He always murmurs when the homework seems difficult to him.
This usage of 'maulburgern' implies speaking indistinctly while expressing one's thoughts.