doubtless
Americanadverb
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without doubt; certainly; surely; unquestionably.
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probably or presumably.
adjective
adverb
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certainly
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probably
adjective
Synonym Usage
Doubtless, undoubtedly, indubitably, unquestionably are adverbs that express certainty. Doubtless, although it sometimes denotes an absolute degree of certainty, more often means “probably,” “presumably,” or “no doubt”: She will doubtless accept the offer. Undoubtedly means “beyond doubt”: undoubtedly the most prolific and popular composer of his time. Indubitably and unquestionably both affirm an unassailable conviction; they differ only in tone, indubitably being appropriate to more formal or learned discourse and unquestionably appropriate in a wider range of contexts and styles: an indubitably (or unquestionably) accurate transliteration of the hieroglyphic text; unquestionably the hottest running back in the league.
Other Word Forms
Etymology
Origin of doubtless
First recorded in 1300–50, doubtless is from the Middle English word douteles. See doubt, -less
Explanation
Use the adverb doubtless to mean "absolutely" or "without question." You could tell your brother that he'll doubtless be thrilled about the birthday present you got for him. You might rule out several neighborhoods when you're looking for a new apartment to rent, knowing they'll doubtless be too expensive for you. When she invites you to dinner, your friend might warn you about her dad's long stories, adding, "He'll doubtless tell you the one about his trip to Europe during college." Doubt is at the heart of doubtless, from the Latin dubitare, "to doubt, question, or hesitate."
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
That is one element of this which the committee is doubtless going to want to probe further, and perhaps where Sir Olly felt on shakiest ground.
From BBC • Apr. 21, 2026
"But we seem to be sleepwalking into a conclusion that will result in the next owner of Thames Water – having, doubtless, many attributes – having none of these attributes."
From BBC • Apr. 15, 2026
They doubtless have some things to tell us, once we lower our voices and listen.
From The Wall Street Journal • Apr. 11, 2026
Many of his followers doubtless find that his most appealing quality, but the rest of the world is no longer amused.
From Salon • Mar. 19, 2026
The experience was not lost on the painters, and doubtless some of the sketches of the “Prelude to the Great Storm” will grace the R. A. and R. I. walls in May next.
From "Dracula" by Bram Stoker
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
