Source : Webster's Revised Unabridged Dictionary (1913)

Retrogressive \Re`tro*gres"sive\, a. [Cf. F. r['e]trogressif.]
   1. Tending to retrograde; going or moving backward; declining
      from a better to a worse state.

   2. (Biol.) Passing from a higher to a lower condition;
      declining from a more perfect state of organization;
      regressive.

Source : WordNet®

retrogressive
     adj : going from better to worse [syn: {retrograde}]