Most gladdening refers to something that brings immense joy or happiness. Antonyms for this phrase would be words that describe opposite emotions, such as depressing, saddening, disheartening, gloomy, or bleak. When we encounter situations or events that fall into this category of antonyms, we may feel frustrated, demotivated, or just generally unhappy. For instance, failing an exam can be disheartening, receiving bad news can be depressing or bleak, and losing a loved one can be saddening. The opposite of most gladdening can vary depending on the individual's perspective and experiences, but they all evoke feelings of negativity, disappointment, or discouragement.