Behaviour, actions, work, treatment, or conditions that are of a higher, more acceptable, or more satisfactory standard than what is currently present or expected.
I didn't think he would leave without telling me — I expected better of him.
Something or someone that is superior in quality, condition, or rank.
In terms of comfort, the second hotel was the clear better of the two.
One's social superiors, especially in rank or status (usually plural "betters").
He was always careful to show respect to his betters.