Ambiguous refers to something that has more than one possible interpretation or a double meaning, a situation or language that is hard to classify or appears obscure. Related words are ambiguously, ambiguousness, ambiguity. Ambiguous comes from the Latin word ambiguus which means having double meaning, changeable.
Ambivalent means to experience mixed or contradictory feelings about something or toward someone. Related words are ambivalently, ambivalency, ambivalence. Ambivalent was originally a psychology term, it is a back-formation from ambivalence. Ambivalent doesn’t appear in the English language until 1929.
Examples
Unless carefully drafted, a rule or statute can be unwittingly ambiguous. (Forbes)
Preacher suspended, referred to investigations for ambiguous reasons (The Daily News Egypt)
It said: “The theory on which the [EU’s] preliminary conclusions rest is so ambiguous that the Commission itself concluded three times that the concern had been resolved,” Google’s lawyers wrote in the document.” (The Register)
And rude behavior can have even more insidious effects than that: People exposed to it tended to interpret even ambiguous and benign behaviors as rude, which then caused them to behave rudely, initiating a whole feedback loop of meanness. (People Magazine)
Call it the ambivalent marriage — not always terrible, but not always great, either. (The New York Times)
ANALYSIS: Irish government deeply ambivalent on Syriza debt deal (The Sunday Business Post)
Obama himself appears to be deeply ambivalent about the goal of destroying ISIS. (The Atlantic)
Malkovich took time out from discussing his upcoming album in a soon-to-be-published interview with Rolling Stone to look back at his ambivalent association with the influential 1999 film. (Rolling Stone Magazine)
The message is that we in York County are, or must be, ambivalent about this world crisis. (The York Daily Record)