What is the meaning of the word "better"?

Definitions:

a superior person having claim to precedence noun
- I was kept in my place by my betters.
changed for the better in health or fitness adjective
- Their health is better now.
comparative of `well' adverb
- in a better or more excellent manner or more advantageously or attractively or to a greater degree etc.
more than half adjective
- argued for the better part of an hour
something superior in quality or condition or effect noun
- a change for the better
the superior one of two alternatives noun
- chose the better of the two
to get better verb
- I bettered over time.
to improve or make something better verb
- Their ideas for bettering the work conditions were well received.
to surpass in excellence verb
- They bettered their own record.