Find Synonyms
certainly Synonyms
Another word for certainly
Choosing another word for certainly depends on context, so the 23 synonyms and similar words below are separated across 3 exact definitions and ranked by match strength.
• adverb (Context 1)
Without any doubt; definitely or unquestionably.
Usage Example
"The new research findings will definitely influence how scientists approach climate modeling in the future."
Strongest
definitely
unquestionably
undoubtedly
indubitably
assuredly
positively
undeniably
Strong
surely
doubtlessly
for sure
• adverb (Context 2)
Used to emphasize a statement, concede a point in an argument, or acknowledge that something is true.
Usage Example
"While the project was admittedly expensive, the long-term benefits to the community outweighed the initial costs."
Strongest
admittedly
granted
undeniably
Strong
indeed
to be sure
of course
undoubtedly
doubtless
clearly
• interjection (Context 3)
Used in conversation to express polite, enthusiastic, or emphatic agreement or consent to a request or question.
Usage Example
""Could you please pass me the conference schedule?" "absolutely, here it is.""
Strongest
absolutely
of course
definitely
sure
by all means
Strong
naturally
gladly
surely
yes
Opposites of certainly
The opposite of certainly shifts depending on context. Common opposites include:
no
doubtfully
questionably
never
no way
uncertainly
dubiously
by no means
• Nearby Words
Cite this Entry
Wordmom. (2026). Synonyms for Certainly. In Wordmom Thesaurus. Retrieved Nov 5, 2026, from https://wordmom.com/synonyms/certainly