The Collaborative International Dictionary of English v.0.48:

Pseudoscorpiones \Pseu`do*scor`pi*o"nes\, n. pl. [NL. See
   Pseudo-, and Scorpion.] (Zool.)
   An order of Arachnoidea having the palpi terminated by large
   claws, as in the scorpions, but destitute of a caudal sting;
   the false scorpions. Called also Pseudoscorpii, and
   Pseudoscorpionina. See Illust. of Book scorpion, under
   Book.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Pseudoscorpiones
    n 1: false scorpions [syn: Chelonethida, order Chelonethida,
         Pseudoscorpionida, order Pseudoscorpionida,
         Pseudoscorpiones, order Pseudoscorpiones]