Ambiguity is the quality of communicating something that is open to more than one interpretation through inexactness.  Its antonym is clarity. Jesus had this to say on clear communication: "All you need to say is simply 'Yes' or 'No'; anything beyond this comes from the evil one."

Any teaching of a Catholic doctrine that is cast in ambiguous terms by a skillful turn of phrase or a clever sleight of hand gives the false impression that the discussion is safely rooted within the parameters of Catholic orthodoxy without realising that it has undercut the full meaning and authority of the doctrine itself. 

There's nothing heroic about ambiguity when dealing with doctrinal truth. It's deception. As Pope Pius X observed, heterodoxy does not operate in this way; it's technique is infiltration "without order and systematic arrangement, in a scattered and disjointed manner."