improvement improvement /ˌɪmˈpruːvmənt/

noun

1. () The act of improving something  ( improvement )
   the act of improving something
    Their improvements increased the value of the property
   their improvements increased the value of the property
   
2. () A change for the better; progress in development  ( betterment , advance , improvement )
   a change for the better; progress in development
     The army made a strategic advance towards enemy territory.
   The army made a strategic advance towards enemy territory.
   
3. () A condition superior to an earlier condition  ( melioration , improvement )
   a condition superior to an earlier condition
    The new school represents a great improvement
   the new school represents a great improvement