colt evil noun2 •(no longer used) A swelling in the genitals of horses.The Colt Evil chiefly affects young stoned colts, which have full liberty with mares before they are able to cover them. — 1838 •(no longer used) Priapism.young folks most apt to love, and by their good wills, saith Lucian, ‘would have a bout with every one they see’: the colt's evil is common to all complexions. — 1624
