The antonyms of the word "un-fulfillment" are numerous, as it refers to a lack of satisfaction or fulfillment. One opposite could be "contentment," which represents a state of being satisfied and fulfilled. Another antonym can be "fulfillment" itself, which means the achievement of a goal or desire leading to a feeling of satisfaction. "Happiness," "pleasure," and "satisfaction" are also antonyms of "un-fulfillment" since they denote a sense of fulfilled needs and desires. On the other hand, antonyms like "discontent," "dissatisfaction," and "unhappiness" emphasize negative feelings contrary to a sense of fulfillment.