scorpionida

from The Century Dictionary.

• noun An order of Arachnida, having pulmotracheate respiration, the cephalothorax indistinctly segmented from the abdomen, a long jointed postabdomen ending in a hook or telson, and long maxillary palpi, or pedipalps, ending in a usually large chelate claw, or pincer; the true scorpions or Scorpiones.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun true scorpions