The word "breadthened" itself does not exist in standard English, but if we were to assume that it is a misspelling of the word "breadthened", its antonyms could be narrowed, condensed, compressed, shrunk, or reduced. These words imply that something has become smaller or more confined, in terms of its range or size. On the other hand, antonyms for an imaginary word "breadthened" could be expanded, enlarged, augmented, broadened, or widened, suggesting that something has become larger or more extensive in its scope or capacity. These words highlight the opposite of contraction or reduction, ultimately leading to a more nuanced and diverse understanding of the topic at hand.