noun

The better one; that which is better.

the Natural History Museum book is by far the better of the two

adjective

Of a more excellent or effective type or quality.

hoping for better weather

superior,finer,of higher quality,greater,in a different class,one step ahead

adverb

More excellently or effectively.

Johnny could do better if he tried

to a higher standard,in a finer way,in a superior way

transitive verb

Improve on or surpass (an existing or previous level or achievement)

bettering his previous time by ten minutes

surpass,improve on,beat,exceed,excel,top,cap,trump,eclipse,outstrip,outdo,outmatch,go one better than