|n. pl.||1.||(Zool.) A division of Arachnoidea, including the daddy longlegs or harvestman (Phalangium) and many similar kinds. They have long, slender, many-jointed legs; usually a rounded, segmented abdomen; and chelate jaws. They breathe by tracheæ. Called also Phalangides, Phalangidea, Phalangiida, and Opilionea.|
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.