The antonyms for the word "is prolific" are words that carry the opposite meaning such as unproductive, barren, sterile, infertile, disappointing, fruitless, uncreative, and unprofitable. These terms suggest a lack of efficiency, creativity, or success in producing something of value, whether it be in the realm of art, literature, or business. While being prolific is often seen as a desirable trait, this list of antonyms serves as a reminder that sometimes, it's quality over quantity that truly matters. So, when seeking to describe a lack of productivity, these antonyms offer a range of options to articulate the desired effect.