equivocal
Meaning: ambiguous, uncertain, undecided
Usage: His intentions were so equivocal that I didn’t know whether he was being chivalrous or sleazy.
ambiguous
Meaning: uncertain, variably interpretable
Usage: Some people think Caesar married Cleopatra for her power, others believe he was charmed by her beauty. His actual reasons are ambiguous.
dubious
Meaning: doubtful, of uncertain quality
Usage: Suspicious that he was only trying to get a raise, she found his praise dubious.