sure

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Impossible to doubt or dispute; certain.
2. adj. Not hesitating or wavering; firm: sure convictions.
3. adj. Confident, as of something awaited or expected: sure of ultimate victory.
4. adj. Bound to come about or happen; inevitable: sure defeat.
5. adj. Having one's course directed; destined or bound: sure to succeed.
6. adj. Certain not to miss or err; steady: a sure hand on the throttle.
7. adj. Worthy of being trusted or depended on; reliable.
8. adj. Free from or marked by freedom from doubt: sure of her friends.
9. adj. Careful to do something: asked me to be sure to turn off the stove.
10. adj. Obsolete Free from harm or danger; safe.
11. adv. Informal Surely; certainly.
12. idiom. for sure Informal Certainly; unquestionably: We'll win for sure.
13. idiom. make sure To establish something without doubt; make certain: Make sure he writes it down.
14. idiom. sure enough As one might have expected; certainly.
15. idiom. to be sure Indeed; certainly.

Century Dictionary and Cyclopedia

1. Confident; undoubting; having no fear of being deceived or disappointed.
2. Certain of one's facts, position, or the like; fully persuaded; positive.
3. Certain to find or retain: with of: as, to be sure of success; to be sure of life or health.
4. Fit or worthy to be depended on; capable of producing a desired effect or of fulfilling requisite conditions; certain not to disappoint expectation; not liable to failure, loss, or change; unfailing; firm; stable; steady; secure; infallible.
5. Certain to be or happen; certain.
6. Undoubted; genuine; true.
7. Out of danger; secure; safe.
8. Engaged to marry; betrothed.
9. See to be sure, below.
10. To make fast by betrothal; betroth.
11. Synonyms and Certain, Positive, etc. See confident.
12. Certainly; without doubt; doubtless; surely.
13. Firmly; securely.
14. To assure; make certain.

Wiktionary

1. adj. Physically secure and certain, non-failing, reliable.
2. adj. Certain in one's knowledge or belief.
3. adj. Certain to act or be a specified way.
4. adv. Without doubt.
5. interj. this sense) Yes, of course.

GNU Webster's 1913

1. adj. Certainly knowing and believing; confident beyond doubt; implicity trusting; unquestioning; positive.
2. adj. Certain to find or retain.
3. adj. Fit or worthy to be depended on; certain not to fail or disappoint expectation; unfailing; strong; permanent; enduring.
4. adj. obsolete Betrothed; engaged to marry.
5. adj. Free from danger; safe; secure.
6. adv. In a sure manner; safely; certainly.

WordNet 3.0

1. adv. definitely or positively (`sure' is sometimes used informally for `surely')
2. adj. infallible or unfailing
3. adj. reliable in operation or effect
4. adj. physically secure or dependable
5. adj. certain to occur; destined or inevitable
6. adj. (of persons) worthy of trust or confidence
7. adj. certain not to fail
8. adj. impossible to doubt or dispute
9. adj. exercising or taking care great enough to bring assurance
10. adj. having or feeling no doubt or uncertainty; confident and assured