The Collaborative International Dictionary of English v.0.48:

Spado \Spa"do\, n.; pl. Spadones. [L., fr. Gr. ?.]
   1. Same as Spade, 2.
      [1913 Webster]

   2. (Law) An impotent person.
      [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

SPADONES, civil law. Those who, on account of their temperament, or some
accident they have suffered, are unable to procreate. Inst. 1, 11, 9; Dig.
1, 7, 2, 1; and vide Impotence.