abdominalia
n. plural-onlyn. the parts of an animal's body that are in the middle, between the chest and the tail. It is a very technical word used mostly in biology to talk about insects or spiders.
n. the posterior segments of an arthropod's body, located between the thorax and the tail. Often used in biological contexts to describe the segmented structure of insects, arachnids, or crustaceans.
The spider's abdominalia are covered in fine, hairy patterns.
In many insect species, the abdominalia contain the primary reproductive organs and the digestive tract.
The researcher noted that the specific arrangement of the abdominalia in this particular species of millipede provides a unique defense mechanism against predators.
Last updated June 22, 2026