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

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

Mentor Running a historic company that delivers white glove service to private clients while also managing a family is doubtless demanding in terms of time, energy and organization. —Kyle Roderick, Forbes.com, 7 Sep. 2025

Nonetheless, the Trump Administration, having now remade American medicine and remedied our higher education, is hard at work reforming our buildings, with memos on movie editing and how to write short stories doubtless on the way. —Adam Gopnik, New Yorker, 6 Sep. 2025

Adjective

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

And the all-boffo, all-the-time production is exhausting (which is doubtless why the rare quiet moments stand out). —Bill Goodykoontz, The Arizona Republic, 29 Nov. 2022

Word History

First Known Use

Adverb

14th century, in the meaning defined at sense 1

Adjective

14th 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