Equivocal is "purposefully ambiguous". So if you use equivocal, you are accusing someone (or something) of trying to mislead you. So equivocal is a type of ambiguity. If a statement is equivocal it is also ambiguous, but if a statement is ambiguous, it is not necessarily equivocal. The dog and the fox got in a fight. After the fight, "it" was so angry it refused to eat for two days. -- This is bad grammar, and so although "it" is "ambiguous", it isn't "equivocal". A. What did you do last night? B. I ate dinner. A. By yourself? B. No. A. With who? B. Some people. A. What people? B. Some friends. Person B is being "equivocal" and as a consequence is also being "ambiguous". As the other person said, obscure is completely different. "I am as tired as Sally in the 4th episode of the relatively unknown drama "Lost in Twilight" when she had to study all night for that test." -- This is not ambiguous at all, it is actually quite specific. But most people won't know the show "Lost in Twilight", and they most likely won't know Sally, and they won't know how tired she was. So it is "obscure". This might have been confusing.

ambiguous, obscure, equIvocal The first and the last are pretty much the same, "obscure" is more about being unknown or uncertain So an ancient book can be obscure if has just been discovered or re-discovered. Its contents can lack clarity and so be seen to be ambiguous or equivocal. Hope that helps.