retrogressive

[Cf. F. rétrogressif.]

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.

adjective

Directed or facing toward the back or rear: backward, retrograde. See precede/follow.

The adjective has one meaning:

Meaning #1: going from better to worse
  Synonyms: declining, deteriorating, failing, regressing, retrograde