adjective B2 Upper-Intermediate Uncommon

doubtful

DOWT-fuhl

Doubtful (adjective) means not certain to happen or be true; uncertain. Example: “It's doubtful she'll finish the report by tonight.”

adjective

Not certain to happen or be true; uncertain.

"It's doubtful she'll finish the report by tonight."

"The outcome of the vote remains doubtful."

Feeling or showing doubt about something.

"He gave a doubtful look when I explained my plan."

"She sounded doubtful about the investment's chances."

Of questionable honesty or reliability.

"The source turned out to be doubtful at best."

How to Use Doubtful

Learner’s notes

In plain EnglishNot sure — used for people who aren't sure, or situations that aren't likely to happen.

Common pairings

doubtful about it is doubtful that doubtful outcome

Word Forms

more doubtful comparative, doubtfuls plural, most doubtful superlative

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It's _____ she'll finish the report by tonight.

Etymology

From Middle English doutfull — built from doubt plus -ful, "full of."

Origin: Middle English

Frequently Asked Questions

What does “doubtful” mean?

The word “doubtful” means not certain to happen or be true; uncertain. In plain terms, not sure — used for people who aren't sure, or situations that aren't likely to happen.

How do you pronounce “doubtful”?

“Doubtful” is pronounced DOWT-fuhl (/ˈdaʊtfəl/ in IPA).

How do you use “doubtful” in a sentence?

Here is “doubtful” used in a sentence: “It's doubtful she'll finish the report by tonight.”

What part of speech is “doubtful”?

“Doubtful” is an adjective.

Where does the word “doubtful” come from?

The word “doubtful” comes from Middle English. From Middle English doutfull — built from doubt plus -ful, "full of.".

Is “doubtful” a common word?

“Doubtful” is an uncommon word in modern English, usually learned at around the B2 level.

How many meanings does “doubtful” have?

“Doubtful” has 3 distinct senses listed in this dictionary. The most common is: not certain to happen or be true; uncertain.