1. (a.) Assured in mind; having no doubts; free from suspicions concerning.

2. (a.) Determined; resolved; -- used with an infinitive.

3. (a.) Not to be doubted or denied; established as a fact.

4. (a.) Actually existing; sure to happen; inevitable.

5. (a.) Unfailing; infallible.

6. (a.) Fixed or stated; regular; determinate.

7. (a.) Not specifically named; indeterminate; indefinite; one or some; -- sometimes used independently as a noun, and meaning certain persons.

8. (n.) Certainty.

9. (n.) A certain number or quantity.

10. (adv.) Certainly.