- Arousing doubt; questionable; open to suspicion.
- After he made some dubious claims about the company, fewer people trusted him.
- 2011, Nigel Jones, "A Tale of Two Scandals", History Today, February 2011, Vol. 61 Issue 2, pages 10–17
- Evasive, womanising, boastful, malicious, untrustworthy, an inveterate gambler who combined his mediocre military career with running a high-class brothel, permanently cash strapped and viciously quarrelsome, his character is as dubious as his unsavoury appearance.
- In disbelief; wavering, uncertain, or hesitating in opinion; inclined to doubt; undecided.
- She was dubious about my plan at first, but later I managed to persuade her to cooperate.
- 2010, John M. Broder, "Global Climate-Change Talks Begin in Cancun With More Modest Expectations", New York Times, November 30, Section A, Column 0, Foreign Desk, page 12
- Last year, President Obama had large majorities in Congress and hopes of passing a comprehensive climate and energy bill. Next year, he faces a new Congress much more dubious about the reality of climate change and considerably more hostile to international efforts to deal with it.
- French: douteux, dubitatif, louche
- German: dubios, fragwürdig, ominös, zwielichtig
- Italian: dubbio, equivoco, ambiguo, losco, bieco, torvo
- Portuguese: dúbio, duvidoso
- Russian: сомни́тельный
- Spanish: dudoso, aleatorio, ambiguo, turbio, equívoco, torvo, avieso