From HomoExcelsior

• One of the two major body divisions of a spider.
• The rear or posterior body part of a spider.
• The part of a spider composed of the fusion of the abdominal segments into a single, soft and usually rounded or cylindrical structure, joined to the cephalothorax anteriorly by the narrow pedicel, and with the spinnerets posteriorly.

Syn: Opisthosoma.