had better/best do something

had better (do something)

Should. You had better listen to what I'm saying before you get yourself into more trouble.
See also: better
Farlex Dictionary of Idioms.

had better/best do something

used to tell somebody what you think they should do: You’d better lock the door before you leave: there are lots of thieves about. Hadn’t you better check to see if the baby is all right? ‘Shall I phone her now?’ ‘You’d best not. She might be asleep.’
See also: better, something
Farlex Partner Idioms Dictionary
See also:
  • had better
  • had better (do something)
  • all to the better
  • so much the better
  • all the better
  • go on to a better land
  • ideally
  • be better placed
  • be well, ideally, better, etc. placed for something/to do something
  • couldn't be better