The term "haddest odor" is quite specific, and finding antonyms for it is not easy. However, we can break down the phrase and identify alternative words that convey the opposite meaning. Instead of "haddest," we could use words like "smell-free," "odorless," or "fragrance-less." For "odor," we could use opposing terms like "aroma," "perfume," or "scent." Hence, the antonyms for "haddest odor" could be considered as "smell-free aroma," "odorless perfume," or "fragrance-less scent." This exercise shows that even if the term may seem challenging, breaking it down and identifying its individual components can provide us with ample antonyms to work with.