Dennis Prager writes in the Jewish Journal:
What does “honor” mean? The Hebrew word for “honor” (ka-bed) consists of the same letters as the Hebrew word for “heavy” (ka-ved). The only difference is a dot in the second letter.
In other words, “honor” means treating one’s parents with the gravity that their position demands. In one of many examples of the genius of Torah Hebrew, the opposite of “honor” is “kalel.” The word is always translated as “to curse,” but its literal meaning is to make light of (from the Hebrew “kal,” light). One curses one’s parents not only if one directs curses at them, but if one treats them lightly.
One honors one’s parents through speech and actions. We do not speak to our parents with the same abandon we do to our peers — no “dude” and no use of expletives are two examples. Actions would include getting up to greet a parent, offering them one’s seat, and maintaining regular contact with one’s parent(s) — such as calling them every week.
Honor does not mean blind obedience. In another great Torah lesson, one learns from Abraham, who disagreed and even argued with God, his Father in Heaven, that one can argue and disagree with one’s father on earth. But one also learns from the way in which Abraham did it how to differ with one’s parent respectfully.