The antonyms of "up-rightly" are numerous, but some of the most commonly used ones include crookedly, improperly, wrongfully, dishonestly, unfairly, and deceitfully. While "up-rightly" implies a sense of morality and ethical behavior, its antonyms suggest the opposite. Crookedly and improperly imply an inefficient or incorrect approach to doing something, whereas wrongfully and unfairly point to a lack of justice or fairness. Additionally, deceitfully and dishonestly denote an inclination to lie or deceive others. In summary, the antonyms of "up-rightly" refer to a range of negative behaviors or attitudes that are in opposition to behaving justly and responsibly.