ambiguous / ambivalent
Unclear meaning versus mixed feeling.
Ambiguous describes words, signals, or situations that can be read more than one way. Ambivalent describes a person who holds opposing feelings at once. A sentence is ambiguous. A voter may be ambivalent. Do not call a person ambiguous when you mean torn, or a sentence ambivalent when you mean unclear.
Examples
UseThe last clause is ambiguous.
UseShe was ambivalent about selling the house.
AvoidShe was ambiguous about selling the house. (Unless her words, not her feelings, were unclear.)