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

• all right
• alright
• assuredly
• certainly
• clearly
• definitely
• easily
• forsooth
• hands down
• inarguably
• incontestably
• incontrovertibly
• indeed
• indisputably
• plainly
• really
• so
• sure
• surely
• truly
• unarguably
• undeniably
• undoubtedly
• unquestionably

Adjective

• assured
• certain
• clear
• cocksure
• confident
• implicit
• positive
• sanguine
• sure

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

This bruin had an entire building all to himself, complete with a stunning view of the lake, doubtless the nicest den for 1,000 miles in any direction. —Lizz Schumer, People.com, 19 Feb. 2025

And if that duo turned away from Moscow, some other NATO members would, given the mutual defense provisions in Article 5 of the NATO treaty, doubtless balk at admitting a country with such dangerously unfinished business with Russia. —The Editors, National Review, 14 Feb. 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