doubtful

Bacteriophages were developed over much of the 20th century by dedicated scientists who battled not just microbes but also doubtful colleagues and corrupt politics.

To be fair to Tapper, it's doubtful he's genuinely surprised at Johnson's priorities.

Former Manhattan prosecutor Diana Florence said that this request makes it doubtful that Trump would face sentencing at the scheduled hearing on 26 November, as the judge will probably accept the prosecutors' proposal.

That's if he ever cared about the noise in the first place, which is doubtful.

For example, experts are doubtful that ICE's 20,000 agents and support personnel would be enough to find and track down millions of undocumented migrants.