Synonyms of doubtless

doubtless 1 of 2

adjective

as in sure

having or showing a mind free from doubt

another one of his doubtless predictions that will never come true

Synonyms & Similar Words

• sure
• confident
• assured
• certain
• positive
• implicit
• sanguine
• clear
• cocksure
• decisive
• resolute
• unhesitating
• self-assured
• unquestioning
• self-confident
• self-conceited
• unwavering
• unfaltering

Antonyms & Near Antonyms

• doubtful
• uncertain
• unsure
• dubious
• hesitant
• indecisive
• unassuming
• wavering
• vacillating
• diffident

doubtless

2 of 2

adverb

ˈdau̇t-ləs 

1

as in certainly

without any question

she is doubtless the one and only girl for me

Synonyms & Similar Words

• certainly
• surely
• definitely
• sure
• probably
• clearly
• undoubtedly
• likely
• really
• assuredly
• easily
• unquestionably
• for certain
• so
• truly
• indeed
• damn well
• undeniably
• indisputably
• plainly
• perhaps
• possibly
• obviously
• by all means
• incontestably
• for sure
• inarguably
• all right
• unarguably
• forsooth
• alright
• conceivably
• incontrovertibly
• by all odds
• hands down
• unmistakably

2

as in probably

by reasonable assumption

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

Synonyms & Similar Words

• probably
• likely
• perhaps
• maybe
• surely
• presumably
• definitely
• certainly
• definitively
• possibly
• assumably
• undoubtedly
• as like as not
• practically
• clearly
• reasonably
• conceivably
• potentially
• plausibly
• assuredly
• unquestionably
• positively
• mayhap
• undeniably
• indisputably
• perchance
• imaginably
• supposedly
• conclusively
• indubitably
• decisively
• really
• truly
• presumedly
• supposably

Antonyms & Near Antonyms

• improbably
• incredibly
• unbelievably
• inconceivably
• implausibly
• unthinkably

Example Sentences

Recent Examples of doubtless

Adjective

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

Like Shannon, Natalie followed a circuitous musical path, dabbling in noise rock and once fronting a band called Satanized, doubtless to the delight of her Pentecostal parents. — Daniel De Visé, SPIN, 13 Sep. 2022

Adverb

But the show’s creatives have been looking to deftly expand Rowling’s beloved source material and will doubtless find some fresh ways to elevate the story. — James Hibberd, HollywoodReporter, 6 May 2026

Savings here and there are doubtless feasible. — Editorial, Boston Herald, 17 Apr. 2026