The definition of the word doubtful is the feeling of uncertainty regarding something or someone. The thing might be an unknown so would need further thought.
The root word of doubtful is "doubt."
Dubious means hesitating or doubtful, questionable in terms of validity or truth.
An evil man is always doubtful. Without a doubt, Wikianswers is the best question and answer site.
The definition of skeptical is “Unbelievable” or “Doubtful”
"doubtful" does not have a prefix. It does, however, have a suffix ('-ful').
You can use the word "doubtful" to express uncertainty or skepticism about something. For example, "It is doubtful that we will finish the project on time," or "She gave a doubtful look at the new proposal."
unlikely
doubtful
It is doubtful that the Fourth of July picnic will be cancelled due to snow.
doubtful.
ambiguous, dangerous, tricky, insecure, doubtful, chancy
Example sentence - It is doubtful the student will graduate as he does not have the credits required.