From Middle English speculacioun, speculation, from Old French speculation (compare French spéculation), from Late Latin speculātiō, from Latin speculor.

Morphologically speculate + -ion

• (America) IPA: /ˌspɛk.jəˈleɪ.ʃən/

speculation

1. (obsolete) The faculty of sight.
   • c. 1606 (date written), William Shakespeare, “The Tragedie of Macbeth”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act III, scene iv]:

     Thou hast no speculation in those eyes.

2. (obsolete) An act of looking at something; examination, observation.
3. The process or act of thinking or meditating on a subject.
   • 1667, John Milton, “Book IX”, in Paradise Lost. […], London: […] [Samuel Simmons], and are to be sold by Peter Parker […]; [a]nd by Robert Boulter […]; [a]nd Matthias Walker, […], →OCLC ↗; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873, →OCLC ↗:

     Thenceforth to speculations high or deep I turned my thoughts.

   • 1726 October 27, [Jonathan Swift], “The Humours and Dispositions of the Laputians Described. […]”, in Travels into Several Remote Nations of the World. […] [Gulliver's Travels], volume II, London: […] Benj[amin] Motte, […], →OCLC ↗, part III (A Voyage to Laputa, Balnibarbi, Glubbdubdribb, Luggnagg, and Japan), pages 16–17 ↗:

     It ſeems, the Minds of theſe People are ſo taken up with intenſe Speculations, that they neither can ſpeak, nor attend to the Diſcourſes of others, without being rouzed by ſome external Taction upon the Organs of Speech and Hearing; for which reaſon, thoſe Perſons who are able to afford it always keep a Flapper (the Original is Climenole) in their Family, as one of their Domeſticks, nor ever walk abroad or make Viſits without him.

4. (philosophy) The act or process of reasoning a priori from premises given or assumed.
5. A conclusion to which the mind comes by speculating; mere theory; notion; conjecture.
   • 1690, William Temple, Miscellanea. The Second Part. […], London: […] T. M. for Ri[chard] and Ra[lph] Simpson, […], →OCLC ↗, [https:// page 23]:

     [N]ear the Age of Socrates lived their Great and Renowned Confutius, who began the ſame Deſign, of reclaiming Men from the uſeless and endleſs Speculations of Nature, to thoſe of Morality.

   • 1849–1861, Thomas Babington Macaulay, chapter 19, in The History of England from the Accession of James the Second, volume (please specify |volume=I to V), London: Longman, Brown, Green, and Longmans, →OCLC ↗:

     To his speculations on these subjects he gave the lofty name of the "Oracles of Reason".

6. (business, finance) An investment involving higher-than-normal risk in order to obtain a higher-than-normal return.
7. The act or practice of buying land, goods, shares, etc., in expectation of selling at a higher price, or of selling with the expectation of repurchasing at a lower price; a trading on anticipated fluctuations in price, as distinguished from trading in which the profit expected is the difference between the retail and wholesale prices, or the difference of price in different markets.
   • 1776, Adam Smith, The Wealth of Nations:

     Sudden fortunes, indeed, are sometimes made in such places, by what is called the trade of speculation.

   • 1883, Francis Amasa Walker, Political Economy:

     Speculation, while confined within moderate limits, is the agent for equalizing supply and demand, and rendering the fluctuations of price less sudden and abrupt than they would otherwise be.

8. A card game in which the players buy from one another trumps or whole hands, upon a chance of getting the highest trump dealt, which entitles the holder to the pool of stakes.
9. (programming) The process of anticipating which branch of code will be chosen and executing it in advance.

• See also Thesaurus:supposition

• French: spéculation
• Portuguese: especulação
• Russian: размышле́ние
• Spanish: especulación

• German: Spekulation, Betrachtung

• French: spéculation
• German: Spekulation
• Portuguese: especulação
• Russian: предположе́ние
• Spanish: especulación

• French: spéculation
• German: Spekulation
• Italian: speculazione
• Portuguese: especulação
• Russian: спекуля́ция
• Spanish: especulación

• Portuguese: especulação
• Spanish: especulación