資料來源 : Webster's Revised Unabridged Dictionary (1913)

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.

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