What is "for the better"

Better \Bet"ter\, n.

1. Advantage, superiority, or victory; -- usually with of; as, to get the better of an enemy.

2. One who has a claim to precedence; a superior, as in merit, social standing, etc.; -- usually in the plural.

   Their betters would hardly be found.
   --Hooker.

   For the better, in the way of improvement; so as to produce improvement. ``If I have altered him anywhere for the better.''
   --Dryden.