doubtful

US /ˈdaʊt.fəl/

UK /ˈdaʊt.fəl/

1.

feeling uncertain about something

:

•

I'm doubtful about his ability to finish the project on time.

•

She gave a doubtful look when he explained his plan.

:

skeptical dubious uncertain hesitant

:

certain sure confident

2.

unlikely to be true or to happen

:

•

It's doubtful that they will agree to our terms.

•

The success of the mission remains doubtful.

:

unlikely improbable questionable

:

likely probable certain

:

doubt no doubt beyond doubt without doubt cast doubt on doubting Thomas beyond a shadow of a doubt