reflex

R1E1F4L1E1X8
/ˈɹiːflɛks//ɹɪˈflɛks/

noun

An automatic response to a simple stimulus which does not require mental processing.

Similar
re-entrantautomaticreflexiveinvoluntaryreflex responsereflex actioninstinctive reflexinnate reflex
Opposite
Less commonScrabble 16

Meanings

nounreflex (plural reflexes)

plural reflexes

  1. An automatic response to a simple stimulus which does not require mental processing.

    For a while, I shall have to make a conscious effort to smile, nod, stand and perform the thousands of little gestures which constitute life on Earth, and then those gestures will become reflexes again.

    1970, Stanisław Lem, trans. Joanna Kilmartin and Steve Cox, Solaris
    1 more example

    He met Luis Suarez's cross at the far post, only for Chelsea keeper Petr Cech to show brilliant reflexes to deflect his header on to the bar. Carroll turned away to lead Liverpool's insistent protests that the ball had crossed the line but referee Phil Dowd and assistant referee Andrew Garratt waved play on, with even a succession of replays proving inconclusive.

    2012 May 5, Phil McNulty, “Chelsea 2-1 Liverpool”, in BBC Sport
  2. human sciencesThe descendant of an earlier language element, such as a word or phoneme, in a daughter language.

    Antonyms: etymon

  3. rarehuman sciencesThe ancestor word corresponding to a descendant.

    The Middle Korean reflex for mey was mwoy 뫼

    2011, Ki-Moon Lee, S. Robert Ramsey, A history of the Korean language
  4. The descendant of anything from an earlier time, such as a cultural myth.

    The superstition of the loup-garou, or werewolf, belongs to the folklore of most modern nations, and has its reflex in the story of "Little Red Riding-hood" and others.

    1898, Christian Brinton, The Century
  5. artsA reflection or an image produced by a reflection; the light reflected from an illuminated surface to one in shade.

    A reflex camera uses a mirror to reflect the image onto a ground-glass viewfinder.

    3 more examples

    Yon gray is not the morning’s eye, ’Tis but the pale reflex of Cynthia's brow.

    c. 1591–1595 (date written), William Shakespeare, “The Tragedie of Romeo and Ivliet”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act III, scene v]

    On the depths of death there swims The reflex of a human face.

    1850, [Alfred, Lord Tennyson], “(please specify |part=Prologue or Epilogue, or |canto=I to CXXIX)”, in In Memoriam, London: Edward Moxon, […], →OCLC

    Lucy is sleeping soundly; the reflex of the dawn is high and far over the sea[.]

    1897, Bram Stoker, Dracula, published 1993, page 88
adjectivereflex (comparative more reflex, superlative most reflex)

comparative more reflex · superlative most reflex

  1. Bent, turned back or reflected.

    the reflex act of the soul, or the turning of the intellectual eye inward upon its own actions

    a. 1677 (date written), Matthew Hale, The Primitive Origination of Mankind, Considered and Examined According to the Light of Nature, London: […] William Godbid, for William Shrowsbery, […], published 1677, →OCLC
  2. Produced automatically by a stimulus.

    It's easier to focus on the particular relationship or object (as in 'pornography', for example) than on the sexist (racist, ageist, etc.) attitudes that generate the almost reflex violence taught in our schools, churches, legal processes, families, mass entertainment, and advertising propaganda.

    1984 February 4, Mike Riegle, “Consent and Violence”, in Gay Community News, volume 11, number 28, page 6
  3. geometryHaving greater than 180 degrees but less than 360 degrees.

    We say that an angle is convex if it is not reflex.

    2001, Esther M. Arkin et al., “On the Reflexivity of Point Sets”, in Algorithms and data structures: 7th International Workshop, WADS 2001: Proceedings, Springer, page 195
    5 more examples

    A polygon is said to be convex when no one of its angles is reflex.

    1878, James Maurice Wilson, Elementary Geometry, MacMillan, page 10

    An angle less than a right angle is said to be acute; one greater than a right angle but less than a straight angle is said to be obtuse; one greater than a straight angle but less than a perigon is said to be reflex or convex.

    1895, David Eugen Smith, Wooster Woodruff Bernan, New Plane and Solid Geometry, page 7

    If the reflex region is the interior of the angle, the dihedral angle is reflex.

    1958, Howard Fehr, “On Teaching Dihedral Angle and Steradian” in The Mathematics Teacher, v 51, National Council of Teachers of Mathematics, page 275

    A reflex edge of a polyhedron is an edge where the inner dihedral angle subtended by two incident faces is greater than 180°.

    1991, B. Falcidieno et al., “Configurable Representations in Feature-based Modelling”, in Eurographics '91: Proceedings, North-Holland, page 145

    P denotes a polygon and r the number of reflex vertices.

    2004, Ana Paula Tomás and António Leslie Bajuelos, “Quadratic-Time Linear-Space Algorithms Generating Orthogonal Polygons with a Given Number of Vertices”, in Computational Science and Its Applications – ICCSA 2004 Proceedings, part 3, Springer, page 117

    Synonyms: re-entrant

  4. paintingIlluminated by light reflected from another part of the same picture.
verbreflex (third-person singular simple present reflexes, present participle reflexing, simple past and past participle reflexed)

present singular third person reflexes · participle present reflexing · participle past reflexed · past reflexed

  1. transitiveTo bend back or turn back over itself.
  2. obsoletetransitiveTo reflect (light, sight, etc.).
  3. obsoletetransitiveTo reflect or mirror (an object), to show the image of.
  4. obsoletetransitiveTo cast (beams of light) on something.

    The ſpring is hindered by your ſmoothering hoſt, For neither rain can fall vpon the earth, Nor Sun reflexe his vertuous beames thereon. The ground is mantled with ſuch multitudes.

    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; reprinted as Tamburlaine the Great (A Scolar Press Facsimile), Menston, Yorkshire; London: Scolar Press, 1973, →ISBN, Act III, scene i
  5. To respond to a stimulus.

Synonyms & antonyms

nounThe descendant of an earlier language element, such as a word or phoneme, in a daughter language.

Opposite

adjectiveHaving greater than 180 degrees but less than 360 degrees.

Similar

More synonyms by meaning

adjectivewithout volition or conscious control

nounan automatic instinctive unlearned reaction to a stimulus

Similar
reflex responsereflex actioninstinctive reflexinnate reflexinborn reflexunconditioned reflexphysiological reaction

Synonym sets from Open English WordNet, CC BY 4.0.

Origin

  1. Late Latinreflexus
  2. Englishreflex

From Late Latin reflexus, past participle of reflectere (“to bend back”), equivalent to re- + flex. Photography sense is from noun sense meaning “reflection”. Compare English reflect.

Full word history & related roots →

Translations

Arabic مُنْعَكَس
  • مُنْعَكَس (munʕakas)automatic response
Bulgarian рефле́кс, огледален
  • рефле́кс (refléks)automatic response
  • огледален (ogledalen)of a type of camera
Catalan reflex
  • reflexautomatic response
Chinese Mandarin 反射
  • 反射 (fǎnshè)automatic response
Czech reflex
  • reflexautomatic response
Dutch reflex, reflex
  • reflexautomatic response
  • reflexthe descendant of an earlier language element, such as a word or phoneme, in a daughter language
Esperanto reflekso
  • refleksoautomatic response
Finnish refleksi, heijaste
  • refleksiautomatic response
  • heijasteautomatic response
French réflexe, continuateur
  • réflexeautomatic response
  • continuateurthe descendant of an earlier language element, such as a word or phoneme, in a daughter language
German Reflex, Kontinuante
  • Reflexautomatic response
  • Kontinuantethe descendant of an earlier language element, such as a word or phoneme, in a daughter language
  • Fortsetzerthe descendant of an earlier language element, such as a word or phoneme, in a daughter language
Greek αντανακλαστικό
  • αντανακλαστικό (antanaklastikó)automatic response
Hindi प्रतिवर्त क्रिया
  • प्रतिवर्त क्रिया (prativart kriyā)automatic response
Hungarian tükörreflexes
  • tükörreflexesof a type of camera
Italian riflesso, riflesso
  • riflessoautomatic response
  • riflessothe descendant of an earlier language element, such as a word or phoneme, in a daughter language
  • continuatorethe descendant of an earlier language element, such as a word or phoneme, in a daughter language
Japanese 反射
  • 反射 (hansha)automatic response
Korean 반사
  • 반사 (bansa)automatic response
Māori kahuki, whetau
  • kahukiautomatic response
  • whetauautomatic response
  • rāwahoof an angle
Polish odruch, refleks
  • odruchautomatic response
  • refleksautomatic response
  • automatautomatic response
  • kontynuantthe descendant of an earlier language element, such as a word or phoneme, in a daughter language
Portuguese reflexo
  • reflexoautomatic response
Russian рефле́кс
  • рефле́кс (refléks)automatic response
Spanish reflejo, reflejo
  • reflejoautomatic response
  • reflejothe descendant of an earlier language element, such as a word or phoneme, in a daughter language
  • continuadorthe descendant of an earlier language element, such as a word or phoneme, in a daughter language
  • réflexof a type of camera
Swedish reflex
  • reflexautomatic response
Tagalog balikusa, pabalik
  • balikusaautomatic response
  • pabalikof an angle
Turkish refleks
  • refleksautomatic response
Vietnamese phản xạ
  • phản xạautomatic response

Rhymes & wordplay

Anagrams

Cite this entry
APA

reflex. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/reflex

MLA

“reflex.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/reflex. Accessed November 3, 2026.

Chicago

WatkinsX Dictionary, s.v. “reflex,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/reflex.

Source: reflex on Wiktionary, CC BY-SA 4.0.