most of something

They were stranded for the best part of a week

in the best way

She would have to manage as best she could

would be well advised to do something

We had best take the train

using the most favourable interpretation or in the most favourable circumstances

The election result was at best uncertain

in one's best mood, health, state of awareness, etc

He's never at his best early in the morning

to do as well as one can; to try one's hardest

to defeat (somebody) or get an advantage over them

to cope with (an unfavourable situation) so as to get some advantage from it

a greater number of games won in a series, bringing overall victory