The word "blow-upped" is not a commonly used word in the English language, and therefore it does not have any widely accepted antonyms. However, if one were to consider the meaning of the word "blow-upped", which could be interpreted as an explosion or a sudden increase in size or intensity, one possible antonym could be "deflated". To deflate means to reduce something in size or force, the opposite of a sudden increase. Another possible antonym could be "shrunk", which means to become smaller, instead of increasing in size. Ultimately, the absence of a standard antonym for the word "blow-upped" highlights the importance of using clear and widely understood language in communication.