Meaning of "doubt" in Essential American English Dictionary

doubt

noun us /dɑʊt/

B1 a state of being uncertain about something, or not trusting someone or something:

I have some doubts about his ability to do the job.
have no doubt

B1 to be certain:

I have no doubt that I made the right decision.
there is no doubt

B1 it is certain:

There is no doubt that he’s a good player.
be in doubt

to not be certain:

The future of the project is in doubt.
without (a) doubt

certainly:

She is without doubt a great writer.
no doubt

used to say that something is very likely:

No doubt she’ll spend the money on her son.

(Definition of “doubt noun” from the Webster's Essential Mini Dictionary © Cambridge University Press)