10 Why do you pass judgment on your brother? Or you, why do you despise your brother? For we will all stand before the judgment seat of God; 11 for it is written,
“As I live, says the Lord, every knee shall bow to me,
and every tongue shall confess  to God.”
12 So then each of us will give an account of himself to God. (Romans 14:9-12 (ESV)
We will all give an account for our own actions. We will all have enough of our own sins to confess at that time. We have no room for judging our brothers. And here we see what is meant by judging, to despise.
Again, the context seems to be stronger brothers despising weaker brothers for not eating meat. I suppose there is this tendency. Often times, we as humans feel we are being judged by those who don’t do the same things as us. If we feel that way it may be time to ask ourselves if we really feel that what we are doing is right or not. Are we fully convinced? From whence comes our guilty conscience? On the other hand, Paul tells the meat eaters that they do nothing wrong by eating meat. So the weak brothers have to also be told to “man up” as it were.
The strong brothers have to bear with the weak brothers, but the weak brothers are also told to bear with the stronger brothers. There is no room for despising each other. What there has to be room for is forgiving each other. In this we learn to grow with one another, edify one another and work with one another. We all have one Lord, and we will all give account to him. But he is our Lord precisely because he has forgiven us, and if he has forgiven us, we too ought to forgive one another.