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

Dual-band Wi-Fi has been cooked in too, doubtless catering for sharing notes, backing up ideas, making sure your secretary is kept up to date on your comings and goings, and so on. —New Atlas, 22 Sep. 2025

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

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

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