AraneinaA*ra`ne*i"na\, n. pl. [NL., fr. L. aranea spider.] (Zo["o]l.) The order of Arachnida that includes the spiders. Note: They have mandibles, modified a poison fa?gs, leglike palpi, simple eyes, abdomen without segments, and spinnerets for spinning a web. They breathe by pulmonary sacs and trache[ae] in the abdomen. See Illustration in Appendix.