The word "un-prolific" refers to something that does not produce many results, or is not productive. Antonyms for this word could include "prolific" itself, meaning something that is highly productive or fruitful. Other antonyms might include words such as "productive," "fruitful," "generative," "proliferous," or "fertile." These words refer to things that are highly efficient in producing results, whether it be in terms of work, creativity, or reproduction. By understanding the antonyms of "un-prolific," we can better express ideas related to productivity and efficiency.