The phrase "were on the up" conveys a sense of progress, improvement, and success. Its antonyms include down, declining, deteriorating, failing, and falling. When something is "on the down," it is losing ground, regressing, and sliding backward. Similarly, declining refers to a gradual decrease or slump, while deteriorating implies a negative change in quality, health, or condition. Failing suggests a lack of success, while falling implies a sudden drop, loss of status, or a decrease in value. Antonyms like these remind us that progress is not always guaranteed, and setbacks are part of life's natural ebb and flow.