doubtful

Definitions

Feeling uncertain or lacking conviction about the truth or reliability of something.

Not likely to happen or be true; improbable.

Of uncertain outcome or quality; questionable.

Examples

It is highly doubtful that the train will arrive on time during this snowstorm.

He looked doubtful when I told him that I had finished the entire project in one afternoon.

Synonyms

uncertain dubious skeptical questionable unsure hesitant ambiguous

Antonyms

certain confident sure definite convinced positive unquestionable