What does arachnida mean?
The definition of arachnida
A*rach”ni*da, n. pl.
Etym: [NL., fr. Gr. (ZoÃ¶l.)
One of the classes of Arthropoda. See Illustration in Appendix.
Note: They have four pairs of legs, no antennÃ¦ nor wings, a pair of mandibles, and one pair of maxillÃ¦ or palpi. The head is usually consolidated with the thorax. The respiration is either by trancheÃ¦ or by pulmonary sacs, or by both. The class includes three principal orders: Araneina, or spiders; Arthrogastra, including scorpions, etc.; and Acarina, or mites and ticks.