Definition of "should"

should

/ʃʊd/

verb
1. (auxiliary) Ought to; indicating opinion, advice, or instruction, about what is required or desirable.
  1. Used to issue an instruction (traditionally seen as carrying less force of authority than alternatives such as 'shall' or 'must').
  2. Used to give advice or opinion that an action is, or would have been, beneficial or desirable.
  3. (informal) With verbs such as 'see' or 'hear', usually in the second person, used to point out something remarkable in either a good or bad way.
  4. In questions, asks what is correct, proper, desirable, etc.
    Quotations
    Next month, Clemons will be brought before a court presided over by a "special master", who will review the case one last time. The hearing will be unprecedented in its remit, but at its core will be a simple issue: should Reggie Clemons live or die?
    2012 August 21, Ed Pilkington, “Death penalty on trial: should Reggie Clemons live or die?”, in The Guardian‎
2. (auxiliary) Ought to; expressing expectation.
  1. Indicates that something is expected to have happened or to be the case now.
  2. Will be likely to (become or do something); indicates a degree of possibility or probability that the stated thing will happen or be true in the future.
3. (auxiliary, subjunctive) Used to form a variant of the present subjunctive, expressing a state or action that is hypothetical, potential, mandated, etc.
  Quotations
  'One kiss, my bonny sweetheart, I'm after a prize to-night, / But I shall be back with the yellow gold before the morning light; / Yet, if they press me sharply, and harry me through the day, / Then look for me by moonlight, / Watch for me by moonlight, / I'll come to thee by moonlight, though Hell should bar the way.'
  1906 August, Alfred Noyes, “The Highwayman”, in Poems, New York, N.Y.: The Macmillan Company; London: Macmillan & Co., published October 1906, part 1, stanza V, page 47
  It was a long weary time, for the Boy was too ill to play, and the little Rabbit found it rather dull with nothing to do all day long. But he snuggled down patiently, and looked forward to the time when the Boy should be well again, and they would go out in the garden amongst the flowers and the butterflies and play splendid games in the raspberry thicket like they used to.
  1921 June, Margery Williams, “The Velveteen Rabbit: Or How Toys Become Real”, in Harper’s Bazar, volume LVI, number 6 (2504 overall), New York, N.Y.: International Magazine Company
  And I'd be a fool right nowIf I should hurt you girlAnd I'd be a fool right nowIf I should leave you girl
  1968 December 8, Henry Cosby, Sylvia Moy, Stevie Wonder (lyrics and music), “I’d Be a Fool Right Now”, in For Once in My Life, performed by Stevie Wonder
  He is noted for coming up with his 'wager', in which he argued that he was prepared to believe in God on the grounds that he had nothing to lose if he was wrong, and everything to gain should he be right.
  2008, Peter Michael Higgins, Number Story: From Counting to Cryptography, page 141 (Google Books view)
4. (auxiliary) simple past of shall
  Quotations
  I was astonished at this polite offer, which my modesty induced me to ascribe more to my uniform than to my own merits, and, as I felt no inclination to refuse the compliment, I said that I should be most happy.
  1833, [Frederick Marryat], chapter IV, in Peter Simple. […], volume I, London: Saunders and Otley, […], published 1834, page 42
5. (auxiliary) An alternative to would with first person subjects.
  1. (formal or literary) Used to express a conditional outcome.
    Quotations
    "If our friends, the Scarecrow and the Tin Woodman, were only with us," said the Lion, "I should be quite happy."
    1900 May 17, L[yman] Frank Baum, The Wonderful Wizard of Oz, Chicago, Ill., New York, N.Y.: Geo[rge] M. Hill Co.
    "Your Silver Shoes will carry you over the desert," replied Glinda. "If you had known their power you could have gone back to your Aunt Em the very first day you came to this country." "But then I should not have had my wonderful brains!" cried the Scarecrow. "I might have passed my whole life in the farmer's cornfield."
    1900 May 17, L[yman] Frank Baum, chapter 23, in The Wonderful Wizard of Oz, Chicago, Ill., New York, N.Y.: Geo[rge] M. Hill Co.
  2. (formal or literary outside certain combinations such as with 'imagine' or 'think') Used to impart a tentative, conjectural or polite nuance.
    Quotations
    I should like to dine with him. I dare say he gives famous dinners.
    1817, Jane Austen, Northanger Abbey
  3. Used to express what the speaker would do in another person's situation, as a means of giving a suggestion or recommendation.
noun
plural shoulds
1. Something that ought to be the case as opposed to already being the case.
  Quotations
  When the golf ball is there, the whole self-interference package — the hopes, worries, and fears; the thoughts on how-to and how-not-to; the woulds, the coulds, and the shoulds — is there too.
  1996, Fred Shoemaker, Extraordinary Golf: The Art of the Possible, page 88
  However, we can address maladaptive shoulds by examining the differences between prior events, causes, proximate causes, and moral responsibility.
  2003, Robert L. Leahy, Overcoming Resistance in Cognitive Therapy‎
  Being a list-o-maniac, I suggested we make a list of the "shoulds" and "shouldn'ts." So in the darkness of hazy sleep, I began to mentally prepare mine. The first item on the "should" side was easy: a sibling for our 3-year-old daughter.
  2008, Working Mother, volume 31, number 8, page 20
verb
third-person singular simple present shoulds, present participle shoulding, simple past and past participle shoulded
1. To make a statement of what ought to be true, as opposed to reality.