Definitions

sure

[shoor, shur] / ʃʊər, ʃɜr /

ADJECTIVE

certain, definite

Synonyms

STRONGEST

assured clear confident convinced positive

WEAK

abiding changeless constant convincing decided doubtless enduring firm fixed for a fact free from doubt genuine incontestable incontrovertible indisputable indubitable never-failing persuaded real satisfied set steadfast steady telling unchangeable unchanging uncompromising undeniable unequivocal unfailing unfaltering unqualified unquestionable unquestioning unshakable unshaken unvarying unwavering valid

Antonyms

STRONGEST

doubtful uncertain unsure

WEAK

doubted dubious humbled indefinite swerving unconfident unself-confident unsteady variable wavering wobbly

ADJECTIVE

physically stable

Synonyms

STRONGEST

fast safe strong

WEAK

firm fixed secure solid staunch steady

Antonyms

WEAK

doubted doubtful dubious humbled indefinite swerving uncertain unconfident unself-confident unsteady unsure variable wavering wobbly

ADJECTIVE

inevitable

Synonyms

STRONGEST

assured certain

WEAK

bound guaranteed indisputable ineluctable inerrant inescapable infallible irrevocable surefire unavoidable unerring unfailing

Antonyms

STRONGEST

doubtful doubting hesitant uncertain

WEAK

doubted dubious humbled indefinite swerving unconfident unself-confident unsteady unsure variable wavering wobbly

ADJECTIVE

self-confident

Synonyms

STRONGEST

assured certain confident decisive positive

WEAK

arrogant composed decided self-assured self-possessed

Antonyms

STRONGEST

doubtful doubting hesitant indefinite uncertain unsure

WEAK

doubted dubious humbled swerving unconfident unself-confident unsteady variable wavering wobbly

Usage

What are other ways to say sure? Sure, the simplest and most general of a group of adjectives indicating full belief and trust that something is true, expresses the mere absence of doubt. Certain suggests that there are definite reasons that have freed one from doubt. Confident emphasizes the strength of the belief or the certainty of expectation felt. Positive implies emphatic certainty, which may even become overconfidence or dogmatism.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“We can make sure foster youth enter adulthood with assets, opportunity and a stronger path to independence.”

From MarketWatch • Jun. 11, 2026

To be sure, SpaceX is selling about $75 billion in stock.

From Barron's • Jun. 11, 2026

If you’re not sure how you feel about that, I’m right there with you.

From Salon • Jun. 11, 2026

Carney walked back those comments the next day, saying officials were working to make sure the Gordie Howe bridge would open as soon as possible.

From The Wall Street Journal • Jun. 11, 2026

Grandma closes her eyes to pray, and I’m pretty sure that Dad has been holding his breath since he turned on the TV.

From "Split the Sky" by Marie Arnold

sure

Usage

Example Sentences

Related Words