Acarpous refers to something that is not producing fruit or seeds, and there are several synonyms that convey a similar meaning. Infertile, barren, sterile, fruitless, unproductive, and nonfruitful are all words that can be used interchangeably with acarpous. Each of these synonyms emphasizes the idea that something is not able to produce the desired outcome or result. Infertile and barren are often used to describe soil or land that is unable to grow plants or crops, while sterile and fruitless typically refer to animals or plants that are unable to produce offspring or seeds, respectively. Unproductive and nonfruitful are more general terms that can be used to describe any situation where a desired outcome is not being achieved.