Lewis & Short

pējōro, āre [pejor], v. a. and n. (postclass.).

  1. I. Act., to render worse: statum suum pejorare, opp. to meliorem facere, Paul. Sent. 2, tit. 18.
  2. II. Neutr., to grow worse: pejorans morbus, Cael. Aur. Acut. 2, 1; id. Tard. 2, 1 fin.