The Collaborative International Dictionary of English v.0.48:

Retrograde \Re"tro*grade\, v. i. [imp. & p. p. Retrograded; p.
   pr. & vb. n. Retrograding.] [L. retrogradare, retrogradi:
   cf. F. r['e]trograder.]
   1. To go in a retrograde direction; to move, or appear to
      move, backward, as a planet.
      [1913 Webster]

   2. Hence, to decline from a better to a worse condition, as
      in morals or intelligence.
      [1913 Webster]