Meaning of “good” - Learner’s Dictionary

good

noun uk us /ɡʊd/
ADVANTAGE [ U ]

B2 something that is an advantage or help to a person or situation:

It's hard work, but it's for your own good.
be no good/not any good

B2 to not be useful, helpful, or valuable:

That diet is no good - you haven't lost any weight yet.
do sb good

B2 to be useful or helpful to someone:

A holiday will do you good.
MORALLY RIGHT [ U ]

what people think is morally right:

Children don't always understand the difference between good and bad.
for good

forever:

When he was 20, he left home for good.
→ See also do sb a/the world of good

(Definition of “good noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)