The Difference Between "Dubious" and "Doubtful"

eHow
June 21, 2011

Deciding the most eloquent or straightforward way to express yourself can be an interminable quest consulting dictionaries and thesauruses. Many terms in the English language seem to have the same meaning, but differ in terms of intensity or context. “Dubious” and “doubtful” are a pair of terms that share similar connotations, but express different degrees of uncertainty or suspicion.

Definition of "Dubious"
The word dubious is an adjective meaning hesitating or doubting. “Sarah looked dubious, but followed her boss's orders.” It can also describe something suspect, or not to be relied upon. The word is sometimes used to mean something morally suspect or of questionable value. “Pyramid schemes have come into disrepute because of dubious sales methods.”

Definition of "Doubtful"
Doubtful is an adjective that means feeling uncertain about something. “Doubtful of the bridge's sturdiness, Tom took another route.” It can also describe something not known with certainty. Something improbable or not established as genuine may be called doubtful. “The new drug was of doubtful effectiveness.”

Etymology and Synonyms
Dubious and doubtful share an etymological root in the Latin dubium, which means “a doubt” and “dubius,” meaning "doubtful." Other terms with similar meanings include ambiguous, enigmatic, equivocal, problematic and questionable.

Which Word to Use
The New Oxford American Dictionary puts the terms in this context: “If you are doubtful about the outcome of a situation, you might be understandably dubious about getting involved in it.” Both words express suspicion, indecision or lack of clarity, but doubtful carries a strong connotation of uncertainty, to the extent that the thing described is presumed to be worthless, invalid, unlikely or doomed to fail. Dubious is not as strong, suggesting hesitation or misgivings. If you are doubtful about the outcome of a situation, you are fairly certain it will not turn out well. If you are dubious, you are wavering in your opinion.

References
“The New Oxford American Dictionary”; dubious; 2011
“The New Oxford American Dictionary”; doubtful; 2011