sure

Adjective

sure (comparative surer, superlative surest)

1. Physically secure and certain, non-failing, reliable.
   • This investment is a sure thing.
   • The bailiff had a sure grip on the prisoner's arm.

   Synonyms:

   certain, failsafe, reliable, sicker

2. Certain in one's knowledge or belief.
   • The very excess of the extravagance, in fact, by suggesting to the reader continually the mere aeriality of the entire speculation, furnishes the surest means of disenchanting him from the horror which might else gather upon his feelings.1827, Thomas De Quincey, On Murder Considered as one of the Fine Arts
   • The Celebrity, by arts unknown, induced Mrs. Judge Short and two other ladies to call at Mohair on a certain afternoon when Mr. Cooke was trying a trotter on the track. The three returned wondering and charmed with Mrs. Cooke; they were sure she had had no hand in the furnishing of that atrocious...1897 December (indicated as 1898), Winston Churchill, chapter IV, in The Celebrity: An Episode, New York, N.Y.: The Macmillan Company; London: Macmillan & Co., Ltd., →OCLC, page 58

   Synonyms:

   certain, positive, wis

3. Certain to act or be a specified way.
   • Be sure to lock the door when you leave.
4. Certain to obtain something.
   • Many people book early in order to be sure of the best seats.
5. (obsolete) Free from danger; safe; secure.
   • Feare not: the Forreſt is not three leagues off, / If we recouer that, we are ſure enough.c. 1590–1591 (date written), William Shakespeare, “The Two Gentlemen of Verona”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and...
6. (obsolete) Betrothed; engaged to marry.
   • c. 1513-1518 (probably date written, published after 1535) Thomas More, History of King Richard III
     The king was sure to Dame Elizabeth Lucy, and her husband before God.
   • I presum'd […] [that] you had been sure, as fast as faith could bind you, man and wife.1632, Richard Brome, The Northern Lass

Adverb

sure (comparative more sure, superlative most sure)

1. (modal) Without doubt, certainly.
   • Sure he's coming! Why wouldn't he?
   • "Did you kill that bear yourself?" ―"I sure did!"
2. (archaic) Without fail, surely.
   • Theſe are the wings ſhall make it flie as ſwift,
     As dooth the lightening: or the breath of heauen,
     And kill as ſure as it ſwiftly flies.c. 1587–1588 (date written), [Christopher Marlowe], Tamburlaine the Great. […] The First Part […], 2nd edition, part 1, London: […] [R. Robinson for] Richard Iones, […], published 1592, →OCLC...

Interjection

1. Yes; of course.
   • "Could you tell me where the washrooms are?" "Sure, they're in the corner over there."
2. Yes; I guess; you could say that; a weak or noncommittal positive response.
   • "Do you like cats?" "Sure."
   • "Do you want me to put this in the garage?" "Sure, go ahead."
3. You're welcome; polite response to being thanked.
   • "Thanks for helping me with that electrical fault." "Sure. Any time."

   Synonyms:

   of course