doubtless

1 of 2

adverb

doubt·​less ˈdau̇t-ləs 

1

: without doubt

2

: probably

doubtless

2 of 2

adjective

: free from doubt : certain

doubtlessly adverb

doubtlessness noun

Synonyms of doubtless

Adverb

• certainly
• surely
• definitely
• sure
• probably
• clearly
• undoubtedly
• likely

Adjective

• sure
• confident
• assured
• certain
• positive

Examples of doubtless in a Sentence

Adverb

she is doubtless the one and only girl for me

doubtless you have heard this story before, but I'll tell it anyway

Adjective

another one of his doubtless predictions that will never come true

Recent Examples on the Web

Adverb

Such moves are routinely cheered on Wall Street and some cuts are doubtless necessary given Paramount’s balance sheet ahead of the company’s third-quarter earnings report to investors next month. —James Hibberd, HollywoodReporter, 31 Oct. 2025

Without an excellent performance from the Italian, Spurs would doubtless be travelling back to north London following a second defeat in four days. —Elias Burke, New York Times, 23 Oct. 2025

Adjective

Add in the doubtless significant number of people under 18 using ChatGPT (who weren't included in the sample at all), and a decent majority of OpenAI's users probably aren't old enough to remember the 20th century firsthand. —ArsTechnica, 15 Sep. 2025

Even moderately keen cornering produces body roll and would bring doubtless admonition from the rear seats. —Mike Duff, Car and Driver, 18 Aug. 2023

Word History

First Known Use

Adverb

14th century, in the meaning defined at sense 1

Adjective

15th century, in the meaning defined above

Kids Definition

doubtless

1 of 2 adverb

doubt·​less ˈdau̇t-ləs 

1

: certainly

2

: probably

doubtless

2 of 2 adjective

: free from doubt : certain

doubtlessly adverb