Indubitably: definition, synonyms, examples

Ever been mid-discussion and been so certain about a fact that it couldn’t possibly be false? Something as certain as the grass is green or that the sun will rise tomorrow morning? 

You may have found yourself searching for the exact word to express your certainty. Maybe undoubtedly or doubtless could fit the bill. 

But no, you’re looking for a stronger word. Something that represents your unwavering certainty. Enter indubitably. 

“What’s that?” you ask.

Indubitably is a relatively unknown word that few English speakers choose to use in either writing or speech. 

But when you understand how to use the word, it can be an original addition to your business writing. 

What does indubitably mean? 

Indubitably is an adverb that means something impossible to question or doubt. 

Here’s how to pronounce it: in-DOO-bit-a-blee

Do you know that something is so true that you can’t possibly doubt it? If so, you could use the word indubitably. 

Keep in mind, that indubitably can’t be used to describe something that probably is true or might be true. 

Indubitably should be used to express something so true that doubt doesn’t even enter the equation. 

If there isn’t one hint of doubt about what you’re talking about, you can say that it’s indubitably true. 

As for indubitable, it’s simply the noun form of the word. For example, you could say: 

The indubitable effect of the wine was that everyone at the dinner party was soon drunk. 

What are the origins of the word indubitably? 

Indubitably has an easily traceable etymology. The word comes straight from the Latin indubitabilis, which is a combination of the prefix “in” meaning not and “dubitabilis” meaning open to doubt. 

Dubitabilis comes from the Latin word dubitare, which means to doubt; this is of course where the noun doubt comes from too. 

It’s thought that indubitably started being used in Middle English during the 15th century.=

We also have the word dubitable meaning doubtable or questionable, but it’s pretty rare. 

What about doubtless and undoubtedly? 

Indubitably shares a close meaning to undoubtedly and doubtless, although it represents a stronger level of certainty. 

Undoubtedly, doubtless, and indubitably are three adverbs that share similar meanings, making them easy to confuse. 

Undoubtedly means without a doubt or unquestionably.

Undoubtedly is a useful adverb when used to express a strong opinion. 

Doubtless means certainly or without a doubt. Doubtless can also mean probably or presumably, making it the least strong of the three adverbs. 

Examples of indubitably in a sentence

Now that you’ve got a good grasp of what indubitably means, you may want to know how to correctly use the adverb in a sentence. 

Correct examples

Earlier, Kirk had described the mission as “straightforward,” but then, though indubitably the bravest of commanders, he was never really the brightest. (The New Yorker)

A human driver indubitably gets tired and must stop driving or else they will be driving erratically and dangerously. (Forbes)

The head is indubitably Cromwell’s: though the provenance is a little cloudy in the early 18th century, it beggars belief that a fraudster of that era would be able to fool forensic science many years later. (The Economist)

However, it is worth noting that the first few sips are indubitably the best. (The Guardian)

One last thing: what are some synonyms for indubitably? 

Indubitably lies on the formal end of the writing spectrum. You’re more likely to read it in a formal document, or in a newspaper than hear it in colloquial speech, for instance. 

Not sure if indubitably is the right word for the message you’re trying to convey? Before you dive into a thesaurus, try one of these related words:

Always think about how certain you are about a fact before you use the word indubitable or indubitably. Both show a high level of certainty.

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