Does mild mean happy
Mild does not mean happy. It means gentle; not serious or dangerous; not sharp or strong on flavor; of only moderate severity. The only instance where mild can be used in reference to happiness is if you are talking about a mild smile.
No, it meansmild - mild and pleasantmild - moderate in type or degree or effect or forcemild - humble in spirit or manner
No. I suggest that you consult a dictionary rather than ask, it would be quicker, although the other answers are correct.