Chaetognathous is a technical term used in zoology to refer to animals that have bristle-like teeth. However, this term may not be well known outside the field of biology. On the other hand, there are several synonyms that can be used to describe these animals, which are not only more common but also easier to understand. For instance, you can use words like bristle-toothed, spiny-toothed, or arrow-worm to describe chaetognathous animals. These words provide a simpler and more descriptive alternative to chaetognathous, making it easier for non-biologists to understand the characteristics of these animals.