Being on the up is often associated with progress and positivity. However, there are several antonyms or opposite words that can be used to express the opposite meaning. These words include being on the decline, going downhill, worsening, deteriorating, declining, sinking, falling, regressing, deteriorating, retrogressing, and deteriorating. When someone is on the decline or going downhill, it means things are getting worse for them or the situation they are in. The word sinking suggests that something was once at a certain level but is now gradually going down. In contrast, deteriorating means progressively deteriorating or becoming worse over time. Ultimately, there are several words that can be used to express the opposite of being on the up.