The AI-powered English dictionary
plural prosomas or prosomata
(zoology) The front segment of a body which is divided into two or more segments, especially the cephalothorax of an arachnid or crustacean. quotations
The front part, called the cephalothorax (or prosoma), is enclosed within a relatively hard and unyielding chitinous shell.
1996, Michael J. Roberts, Spiders of Britain and Northern Europe, Collins, published 1996, page 12