(1) Holding opposite feelings and attitudes at the same time toward someone or something. (2) Continually wavering between opposites or alternate courses of action.
Example:
He was extremely ambivalent about the trip: he badly wanted to travel but hated to miss the summer activities at home.
Ambivalent is a fairly new word, less than a hundred years old, but it is ultimately related to the Latin verb valere, which means "to be strong." An ambivalent person is someone who has strong feelings on more than one side of a question or issue. We might feel ambivalence about accepting a high-paying job that requires us to work long hours, or about lending money to someone we like but don't know well. Anyone who has ever been on a diet and been offered something like a Tutti-Frutti Chocolate Banana Sunday El Supremo probably knows what it's like to feel ambivalent.