Source : Webster's Revised Unabridged Dictionary (1913)

Ridgeling \Ridge"ling\, n. [Prov. E. riggilt, riggot, ananimal
   half castrated, a sheep having only one testicle; cf. Prov.
   G. rigel, rig, a barrow hog, rigler a cock half castrated.]
   (Zo["o]l.)
   A half-castrated male animal.

Source : WordNet®

ridgeling
     n : a colt with undescended testicles [syn: {ridgling}, {ridgel},
          {ridgil}]