"Are prolific" refers to the quality of being abundant, fruitful, and productive. On the other hand, antonyms for this phrase may include words like barren, unproductive, and infertile. These words point to situations where productivity and abundance are lacking, and where growth is stymied. Other antonyms for "are prolific" include words like scarce, insufficient, and inadequate. These words highlight situations where things are not abundant and where there is a lack of resources. Thus, the antonyms for "are prolific" underscore the importance of abundance, productivity, and growth, as well as the negative impact of the opposite qualities.