peraeopod

from The Collaborative International Dictionary of English v.0.48

Peraeopod \Pe*rae"o*pod\, n. [Gr. perai^os on the opposite side
   + -pod.] (Zool.)
   One of the thoracic legs of a crustacean. See Illust. of
   {Crustacea}.
   [1913 Webster]