What does undoubtedly mean?
Undoubtedly is an English adverb meaning “without doubt” or “certainly.” It states that a claim, outcome, or judgment is highly certain and may also convey conviction about the speaker’s assessment: “The evidence is strong; the explanation is undoubtedly the right one.” The word is formal enough for academic, professional, and persuasive writing but remains standard in ordinary speech, where it can add emphasis. Unlike the blunt “obviously,” it does not necessarily imply that the matter should have been apparent to everyone, although its force can make it sound assertive. It is especially useful when the certainty is genuine and important to emphasize, as in “undoubtedly the best choice.” Undoubtedly belongs to a broader family built around doubt, including undoubted, doubtful, and doubtless. It is more confident than expressions such as “probably” or “likely,” and its certainty should be proportional to the evidence supporting the statement.
adverbUsed to say that something is certainly true or will certainly happen, especially when expressing strong belief or conviction.
- Certainly or without doubt; used to express strong confidence that something is true or will happen.
"The careful research undoubtedly improved the accuracy of the final report."
"The witness undoubtedly remembered the route, having travelled it many times."
"Undoubtedly, further study will reveal new details about the manuscript."
Undoubtedly turns a simple denial of doubt into a confident declaration: what is doubted is, by definition, no longer in question.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of undoubtedly
Undoubtedly developed in English from the adjective undoubted, meaning “not doubted,” with the suffix -ly, and the form has been in use since the early modern period. Undoubted itself was constructed with un-, doubt, and -ed. Doubt comes through Old French from Latin dubitare, and the same root underlies related English words such as doubtful and doubtless.
Related word forms
How undoubtedly is actually used
The word is neutral to formal in tone and is common in academic, professional, and persuasive prose. It can be emphatic, so it is most appropriate when the evidence genuinely supports the stated certainty.
Easily confused with undoubtedly
Undoubted is normally an adjective describing a noun, as in “an undoubted success,” whereas undoubtedly is an adverb qualifying a verb, clause, or statement.