If something is ambiguous it has more than one possible meaning, and so is obscure or difficult to understand: When I asked Stuart if he condemned my action he gave me an ambiguous answer; The message was perfectly clear and not in the least ambiguous. If a person is ambivalent they have an uncertain attitude or feeling towards someone or something: The French are ambivalent about royalty: they abolished their own monarchy but are very interested in the British royal family. A common error is to use ambivalent instead of ambiguous.
