I know that it can be used as an advice, like should and ought to, for example, but didn't know that it could be a way of saying bad things to someone as @ggoodrich50
wrote. By the way, thank you for the answers, guys.
@Ale_Di, what I really wanted to know, is the complete meaning of the word in all of its contexts, got it?
I know now that it can be used for advice like:
You had better see a doctor.
You ought to see a doctor.
You should see a doctor.
and, like a rude answer, like:
What do you think about dinner?
— Well, I have had better!
But, It has been left me two doubts:
1. "Had better" as advice is stronger rather than "Ought to and Should"?
2. Is there any other meaning for "Had better"?