Source : Webster's Revised Unabridged Dictionary (1913)

Ginglymus \Gin"gly*mus\, n.; pl. {Ginglymi}. [NL., fr. Gr. ? a
   hingelike joint, a ball and socket joint.] (Anat.)
   A hinge joint; an articulation, admitting of flexion and
   extension, or motion in two directions only, as the elbow and
   the ankle.

Source : WordNet®

ginglymus
     n : a freely moving joint in which the bones are so articulated
         as to allow extensive movement in one plane [syn: {hinge
         joint}, {ginglymoid joint}]
     [also: {ginglymi} (pl)]