Etymology Inherited from Middle English symple, from Old French simple, from Latin simplex (“simple”, literally “onefold”) (as opposed to duplex (“double”, literally “twofold”)), from semel (“the same”) + plicō (“to fold”). See same and fold. Compare single, singular, simultaneous, etc. Partially displaced native English onefold.
Uncomplicated; lacking complexity; taken by itself, with nothing added.
We are engaged in a great work, a treatise on our river fortifications, perhaps? But since when did army officers afford the luxury of amanuenses in this simple republic?1910, Emerson Hough, chapter I, in The Purchase Price: Or The Cause of Compromise, Indianapolis, Ind.: The Bobbs-Merrill Company, →OCLC:
Primitive people, colossally ignorant of the cause of disease and of curative processes, attributed to supernatural agencies any causes and effects for which their simple minds could give no natural explanations.1940, Rosetta E. Clarkson, Green Enchantments: The Magic Spell of Gardens, The Macmillan Company, page 253:
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The simplest soliton is the domain wall with co-dimension one, and the next simplest is the vortex with co-dimension two, whereas the co-dimension three (four) soliton is called monopole (instanton).2006, M. Eto et al., “Solitons in Supersymmetric Gauge Theories”, in Particles, Strings and Cosmology, →ISBN, page 266:
The importance of Nowruz is reflected in an elaborate sabzi polo, the herbed rice capped with a crunchy tahdig, the crust formed from lettuce, rice mixed with yogurt or lavash or another thin flatbread. On Wednesday night, I opted for sheveed polo, a simpler and quicker dill rice, but I can’t wait to nail that crunchy tahdig tonight.2026 March 15, Genevieve Ko, “‘This Is the Best Dish I Have Ever Made From NYT Cooking’”, in The New York Times, →ISSN, archived from the original on 15 Mar 2026:
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Easy; not difficult.
There is no simple way to define precisely a complex arrangement of parts, however homely the object may appear to be.2001, Sydney I. Landau, Dictionaries: The Art and Craft of Lexicography, Cambridge University Press, →ISBN, page 167:
Point-free coding is a byproduct of adopting declarative programming. You can use point-free coding without FP. But because point-free is all about improving the readability of code at a glance and making it simpler to parse, having the guarantees imposed by FP furthers this cause.2021, Luis Atencio, The Joy of JavaScript, Simon and Schuster, →ISBN, page 104:
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Without ornamentation; plain.
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Free from duplicity; guileless, innocent, straightforward.
Full many fine men go upon my score, as simple as I stand here, and I trust them.1605, Iohn Marston [i.e., John Marston], The Dutch Courtezan. […], London: […] T[homas] P[urfoot] for Iohn Hodgets, […], →OCLC, (please specify the page):
Must thou trust Tradition's simple tongue?1812, Lord Byron, “Canto I”, in Childe Harold’s Pilgrimage. A Romaunt, London: […] [F]or John Murray, […]; William Blackwood, Edinburgh; and John Cumming, Dublin; by Thomas Davison, […], →OCLC, stanza XXXVI:
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Nothing is more simple than greatness; indeed, to be simple is to be great. The vision of genius comes by renouncing the too officious activity of the understanding, and giving leave and amplest privilege to the spontaneous sentiment.1838 July 24, Ralph Waldo Emerson, “Literary Ethics. An Oration Delivered before the Literary Societies of Dartmouth College, July 24, 1838”, in Nature, Addresses, and Lectures (Emerson’s Complete Works; I), Riverside edition, London: The Waverley Book Company, published 1883, →OCLC, page 160:
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Undistinguished in social condition; of no special rank.
Garak: Who would want to kill me, a simple tailor? / Odo: A simple tailor? A simple tailor who used to be an agent of the Obsidian Order!1995 April 24, Improbable Cause (Star Trek: Deep Space Nine), season 3, number 20 (Science Fiction), Paramount Domestic Television, →OCLC:
‘That was a symple cause,’ seyde Sir Trystram, ‘for to sle a good knyght for seyynge well by his maystir.’1470–1485 (date produced), Thomas Malory, “Capitulum LV”, in [Le Morte Darthur], book X (in Middle English), [London: […] by William Caxton], published 31 July 1485, →OCLC; republished as H[einrich] Oskar Sommer, editor, Le Morte Darthur […], London: David Nutt, […], 1889, →OCLC:
› Structurally uncomplicated. › Being non-trivial, and admitting no proper…
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Algebra, Engineering, Group theory, Heading, Mathematics, Natural sciences, Physical sciences, Sciences, TechnicalBroadly, Of a group, Of an algebraic structure Being non-trivial, and having no proper non-trivial normal subgroups (equivalently, no proper non-trivial quotient groups).
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Algebra, Engineering, Heading, Mathematics, Natural sciences, Physical sciences, Sciences, TechnicalBroadly, Of a module, Of an algebraic structure Being non-trivial, and having no proper non-trivial submodules (equivalently, no proper non-trivial quotient modules).
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Algebra, Engineering, Heading, Mathematics, Natural sciences, Physical sciences, Sciences, TechnicalBroadly, Of a ring, Of an algebraic structure Being non-zero, and having no proper non-zero two-sided ideals (equivalently, no proper non-trivial quotient rings). For commutative rings, this definition coincides with that of a field.
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Algebra, Engineering, Heading, Mathematics, Natural sciences, Physical sciences, Sciences, TechnicalBroadly, Universal, Of an algebraic structure Containing more than one element, and such that the only congruences on the structure are the diagonal relation (the equivalence relation a≡b⟺a=b) and the universal relation (the equivalence relation such that a≡b for all a,b). Equivalently, containing more than one element and having no proper non-trivial quotient algebras.
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Algebra, Category theory, Computing, Engineering, Heading, Mathematics, Natural sciences, Physical sciences, Sciences, TechnicalBroadly, Of an algebraic structure Being non-isomorphic to the terminal object, and such that its only quotient objects (up to isomorphism) are the terminal object and itself.
Of an object in a category with a terminal object
› Structurally uncomplicated.
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Algebra, Engineering, Heading, Mathematics, Natural sciences, Physical sciences, Sciences, TechnicalOf a Lie algebra Being non-abelian and having no proper non-zero ideals. (Note that this is non-equivalent to the usual algebra sense; in particular, the abelian Lie algebra of dimension 1 over any given field is non-trivial and has no proper non-zero ideals, but is by convention not considered simple.)
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Engineering, Heading, Mathematics, Measure theory, Natural sciences, Physical sciences, Sciences, TechnicalOf a real-valued function Equal to a finite linear combination of indicator functions on measurable sets.
Engineering, Heading, Natural sciences, Physical sciences, Technical Using steam only once in its cylinders, in contrast to a compound engine, where steam is used more than once in high-pressure and low-pressure cylinders. (of a steam engine)
Chesapeake & Ohio turned to simple articulateds, for instance, simply because its Alleghany tunnels would not accommodate the low-pressure forward cylinders of larger compounds.1959, David P. Morgan, editor, Steam's Finest Hour, Kalmbach Publishing Co., page 6:
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Biology, Engineering, Heading, Natural sciences, Physical sciences, Technical, Zoology Consisting of a single individual or zooid; not compound.
A medicine […] whose simple touch / Is powerful to araise King Pepin.c. 1604–1605 (date written), William Shakespeare, “All’s Well, that Ends Well”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act II, scene i]:
"Yes; as well versed in the art of intrigue, I should think, as if she had been brought up in attendance in a court, instead of being a simple butler's daughter, in a gloomy old pile like this!"1859, Ned Buntline, chapter XCIV, in Seawaif; Or, The Terror of the Coast, New York: Frederic A. Brady, page 117:
Etymology Inherited from Middle English symple, from Old French simple, from Latin simplex (“simple”, literally “onefold”) (as opposed to duplex (“double”, literally “twofold”)), from semel (“the same”) + plicō (“to fold”). See same and fold. Compare single, singular, simultaneous, etc. Partially displaced native English onefold.
Medicine, Pharmacology, Sciences A herbal preparation made from one plant, as opposed to something made from more than one plant.
Dere is some simples in my closet, dat I vill not for the varld I shall leave behind.c. 1597 (date written), William Shakespeare, […] [T]he Merrie Wiues of Windsor. […] (First Quarto), London: […] T[homas] C[reede] for Arthur Ihonson, […], published 1602, →OCLC, [Act I, scene iv]:
I know there are some simples, which in operation are moistening and some drying.1603, Michel de Montaigne, chapter 37, in John Florio, transl., The Essayes […], book II, London: […] Val[entine] Simmes for Edward Blount […], →OCLC:
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[W]hat Virtue there is in this Remedy lies in the naked Simple it ſelf, as it comes over from the Indies, and in the Choice of that which is leaſt dried, or periſhed by the Voyage.a. 1700 (date written), William Temple, “Of Health and Long-life”, in Miscellanea. The Third Part. […], London: […] Jonathan Swift, […] Benjamin Tooke, […], published 1701, →OCLC, pages 183–184:
The first fellow that picked an herb to cure himself had a bit of pluck. Simples. Want to be careful.1922 February, James Joyce, Ulysses, Paris: Shakespeare and Company, […], →OCLC:
The venerable carryall, formerly brimming with all manner of esoteric pamphlets and witch's simples, now overflowed with a cascade of soft toys, juice bottles, tissues, linen books for infants, […]2003, Dolores Stewart Riccio, Charmed Circle, Kensington Books, →ISBN, page 12:
Peter van Inwagen, for example, believes that there are no ordinary objects, no chairs or shirts or shoes. Right here there are just some simples — atoms or whatever — arranged shoe-wise.2021 September 14, Michael David Stevens, 10:41 from the start, in Do Chairs Exist?:
But it is a melancholy of mine own, compounded of many simples, extracted from many objects, and indeed the sundry contemplation of my travelsc. 1598–1600 (date written), William Shakespeare, “As You Like It”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act IV, scene i]:
Etymology Inherited from Middle English symple, from Old French simple, from Latin simplex (“simple”, literally “onefold”) (as opposed to duplex (“double”, literally “twofold”)), from semel (“the same”) + plicō (“to fold”). See same and fold. Compare single, singular, simultaneous, etc. Partially displaced native English onefold.