had better

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

Also, had best. Ought to, should. For example, You had better finish this one before starting another, or We had best be going. [Mid-1400s] Also see you'd better believe it.
See also: better
The American Heritage® Dictionary of Idioms by Christine Ammer.

had better

/best Usage Problem
To be wise or obliged to; should or must: He had better do what he is told. You had best bring a raincoat in this weather.
See also: better
American Heritage® Dictionary of the English Language, Fifth Edition.
See also:
  • had better (do something)
  • had better/best 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