undoubtedly
6 synonyms and 0 antonyms for undoubtedly, grouped by meaning and by how common each one is.
Adv — Without any doubt; certainly.
Synonyms
Everyday swaps
Common words most readers know — safe in any writing.
Rare, literary or technical
Precise, but they will stand out — check the sense before using one.
How to use undoubtedly
The word patterns that sound natural to a native speaker.
Etymology
From Middle English undoutedly, built from undoubted plus -ly.
Full origin of undoubtedly →Frequently asked questions
What does “undoubtedly” mean?
The word “undoubtedly” means without any doubt; certainly. In plain terms, used to say something is certainly true, with no room for doubt.
How do you pronounce “undoubtedly”?
“Undoubtedly” is pronounced uhn-DOW-tihd-lee (/ʌnˈdaʊtɪdli/ in IPA).
How do you use “undoubtedly” in a sentence?
Here is “undoubtedly” used in a sentence: “This is undoubtedly the best meal I've had all year.”
What part of speech is “undoubtedly”?
“Undoubtedly” is an adverb.
Where does the word “undoubtedly” come from?
The word “undoubtedly” comes from Middle English. From Middle English undoutedly, built from undoubted plus -ly.
Is “undoubtedly” a common word?
“Undoubtedly” is a fairly common word in modern English, usually learned at around the B2 level.
What is the difference between "undoubtedly" and "probably"?
"Undoubtedly" expresses full certainty with no room for doubt, while "probably" signals likelihood but leaves open the chance of being wrong. Choosing "undoubtedly" makes a statement far stronger than "probably."
What is the difference between "undoubtedly" and "doubtless"?
Both mean without doubt, but "undoubtedly" is more emphatic and common in modern writing, while "doubtless" can sometimes carry a hint of assumption, closer to "presumably." In most contexts they are interchangeable, as in "she will undoubtedly succeed."
Where should "undoubtedly" go in a sentence?
As an adverb, "undoubtedly" is flexible: it can open a sentence ("Undoubtedly, he was right"), sit before the main verb ("he undoubtedly knew"), or follow a form of "be" ("she was undoubtedly correct"). Placing it next to the idea it emphasises usually reads most naturally.
Is "undoubtedly" formal or informal?
"Undoubtedly" suits both formal and everyday writing, but it is especially common in academic and persuasive contexts where a writer wants to signal certainty. In casual speech, people often prefer shorter words like "definitely" or "for sure."