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.

"This time, we have to make sure we start on the front foot," he insists.

From BBC • Jun. 10, 2026

However, transfers can have unintended consequences, including Medicaid penalties and tax implications, so make sure you seek out legal counsel before you make any sudden moves.

From MarketWatch • Jun. 10, 2026

The administration is working with Anthropic and OpenAI to control who has access to their best products to make sure the companies are protecting national security.

From The Wall Street Journal • Jun. 9, 2026

Willy Lee of SuRo Capital, an investor in OpenAI already, is sure that all three IPOs will hit their marks.

From Barron's • Jun. 9, 2026

I spit out the question, even though I’m pretty sure I’m not ready to hear the answer.

From "Split the Sky" by Marie Arnold

sure

Usage

Example Sentences

Related Words