What is the Meaning of the Expression
HAD BETTER?

Definition:

HAD BETTER is similar to should, except that should is advice and HAD BETTER is used to warn about a possible negative result

Sometimes HAD is omitted.

Follow HAD BETTER with a base verb.

Examples:

1. You better phone your sister back; it’s almost 10:00 p.m. in her city.

2. You had better be telling me the truth!

3. You’d better slow down. The roads are icy.