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.
Many of the works on display doubtless make for difficult viewing, but shock and disgust are not the point.
From The Wall Street Journal ● Aug. 3, 2026
Starting at fly-half against Italy on Saturday, she will doubtless have the opportunity to extend her streak, even if England are unlikely to need more last-gasp, long-range heroics.
From BBC ● May 6, 2026
They doubtless have some things to tell us, once we lower our voices and listen.
From The Wall Street Journal ● Apr. 11, 2026
Lorne Michaels doubtless has her on speed dial.
From Los Angeles Times ● Mar. 23, 2026
"That would doubtless explain why you are making so much more of the substance than before."
From "A Clash of Kings" by George R.R. Martin
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.
