pereion [puh-rahy-on, -rey-, -ree-] Word Origin noun, plural pe·rei·a [puh-rahy-uh, -rey-uh, -ree-uh] /pəˈraɪ ə, -ˈreɪ ə, -ˈri ə/.
- (in a crustacean) the thorax.
Origin of pereion 1850–55; New Latin, representing Greek peraiôn (present participle of peraioûn to carry about, transport); so called from the location of the legs on the thorax