ought

Etymology 1

From Middle English oughte, aughte, aȝte, ahte, from Old English āhte, first and third person singular past tense of Old English āgan (“to own, possess”), equivalent to owe + -t. Cognate with Sanskrit ईश्वर (īśvará, “capable of, liable”).

verb

1. (obsolete) simple past of owe

verb

1. (auxiliary) Indicating duty or obligation.
   I ought to vote in the coming election.
2. (auxiliary) Indicating advisability or prudence.
   You ought to stand back from the edge of the platform.
3. (auxiliary) Indicating desirability.
   He ought to read the book; it was very good.
4. (auxiliary) Indicating likelihood or probability.
   We ought to arrive by noon if we take the motorway.
   My hopes wa'n't disappointed. I never saw clams thicker than they was along them inshore flats. I filled my dreener in no time, and then it come to me that 'twouldn't be a bad idee to get a lot more, take 'em with me to Wellmouth, and peddle 'em out. Clams was fairly scarce over that side of the bay and ought to fetch a fair price. 1913, Joseph C. Lincoln, chapter 3, in Mr. Pratt's Patients

pron

1. Alternative spelling of aught; anything
   Is it a small benefit, that I am placed there […] where I see no drunken comessations, no rebellious routs, no violent oppressions, no obscene rejoicings, nor ought else that might either vex or affright my soul? 1658, Joseph Hall, The Devout Soul, Or, Rules of Heavenly Devotion Also the Free Prisoner, Or, the Comfort of Restraint

adv

1. Alternative spelling of aught; at all, to any degree.

noun

1. A statement of what ought to be the case as contrasted with what is the case.
   There are value judgments that are not reducible to observable matters of fact, and there are oughts that cannot be construed as hypothetical and, therefore, cannot be converted into statements of fact. 1996, Mortimer Jerome Adler, The Time of Our Lives: The Ethics of Common Sense
   Is there a fallacy involved in deriving an ought from a set of exclusively factual or descriptive premises? 2004, Jacques Maritain, John G. Trapani, Truth Matters: Essays in Honor of Jacques Maritain

Etymology 2

noun

1. Alternative spelling of aught; cipher, zero, nought.