: agreeing with what is considered morally right or good : fair. : treating people in a way that is considered morally right.

What does it mean to be just?

Just means "fair." When something is morally and ethically sound, it's just. If you are a just teacher, you won't give your student an F just because his mother is rude to you.

What word means morally right or just?

Some common synonyms of moral are ethical, noble, righteous, and virtuous. While all these words mean "conforming to a standard of what is right and good," moral implies conformity to established sanctioned codes or accepted notions of right and wrong.