The word wrong itself
Old joke- the word spelled wrong in the dictionary is "wrong"!
The word that is always spelled incorrectly in the dictionary is INCORRECTLY. ha ha ha
According to the dictionary this isn't a real word or you spelled it wrong in the question.
Since it doesn't recognize the word as belong to its dictionary, Microsoft Word will tell you that you have spelt it wrong until you add it to the dictionary. After you have added it to the dictionary, it will recognize the word from then on.
acording to my dictionary you spelled much wrong you wrote mush and it is m-u-c-h much means a lot or plenty
Sign up for an English class. Or take a look at an american dictionary, because you spelled English wrong...