Adjective

(en adjective)

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.

Adjective

(en adjective)

Having, or expressing doubt; questioning.

* {{quote-magazine, year=2012, month=March-April

, author=Colin Allen , title=Do I See What You See? , volume=100, issue=2, page=168 , magazine=(American Scientist) citation , passage=Numerous experimental tests and other observations have been offered in favor of animal mind reading, and although many scientists are skeptical , others assert that humans are not the only species capable of representing what others do and don’t perceive and know.}}

My teacher was skeptical when I told her my dog ate my homework.

I can see why people are so skeptical [sic] about him, but I think he's on to something here. (regarded by organizations such as the BBC as an error)

Of or relating to skepticism or the skeptics.