This is the 14719th most frequent German word.
niedermachen
"To bring down, crush, or criticize harshly."
"Niedermachen" here means to criticize or make something seem worthless.
Er hat ihre Ideen vor der Gruppe niedergemacht.
He tore down her ideas in front of the group.
In this sentence, "niedermachen" conveys the meaning of overwhelming someone emotionally or mentally.
Nach dem Streit fühlte sie sich emotional niedergemacht.
After the argument, she felt emotionally torn down.
Here, "niedermachen" is used to describe severe criticism or harsh judgment of something.