||A*ra`ne*i"na (&adot;*rā`n&esl;*ī"n&adot;), n. pl. [NL., fr. L. aranea spider.] (Zoöl.) The order of Arachnida that includes the spiders.

&fist; They have mandibles, modified as poison fangs, leglike palpi, simple eyes, abdomen without segments, and spinnerets for spinning a web. They breathe by pulmonary sacs and tracheæ in the abdomen. See Illustration in Appendix.