1. Getting higher or more vigorous
   "an improving economy";
   - up

1. To make better
   "The editor improved the manuscript with his changes";
   - better, amend, ameliorate, meliorate, mend
    
2. Get better
   "The weather improved toward evening";
   - better, ameliorate, meliorate

See also: rising

Type of: alter, change, change state, modify, turn

Antonym: decline

Encyclopedia: Improving