Quizzes like this are in crossword-ese. Which means that my goal is not to give a complete and full definition of any term. I'm going to write a few words, not a whole paragraph. Dutch people who settled in South Africa were called Boers. Is that wrong?
Lots of words go through shifts in their definition. Sometimes they co-exist, sometimes the old meaning disappears completely. (Examples in the same area are, dull, sharp, bright, dim, etc they all originally meant the literal meaning, but came to be an abstract reference to someone's intelligence).
In dutch the old word for mute was stom which nowadays means stupid, so followed a similar pattern as in english. (But stom/stupid has a narrower meaning in dutch, it is more about dislike "stupid school" "stupid shoes" etc than intelligence. Like in english you can use it for dislike but also say somebody is stupid meaning he is not smart. We use the word dom(dumb) in that case.
And then there is shtumm. Very surprised when I first heard that in english. (Which comes via yiddish from german stumm) And only means mute (and nót also dumb or stupid if I'm not mistaken