axis

• (Received Pronunciation) IPA^(key): /ˈæksɪs/
• (General American, Canada, General Australian) IPA^(key): /ˈæksɪs/, /ˈæksəs/

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• (New Zealand) IPA^(key): /ˈɛksəs/
• Rhymes: -æksɪs, -æksəs
• Hyphenation: ax‧is

Borrowed from Latin axis (“axle, axis”) in the 16th century. Via Latin cognate with ala, aisle, atelier. Via Proto-Indo-European *h₂eḱs- cognate with inherited English axle and borrowed axo-, axon.

axis (plural axes or (rare) axiis)

1. (geometry) An imaginary line around which an object spins (an axis of rotation) or is symmetrically arranged (an axis of symmetry).
   • 2012 March, Henry Petroski, “Opening Doors”, in American Scientist‎^[1], volume 100, number 2, pages 112–3:

     A doorknob of whatever roundish shape is effectively a continuum of levers, with the axis of the latching mechanism—known as the spindle—being the fulcrum about which the turning takes place.

   The Earth rotates once a day on its axis

2. (mathematics) A fixed one-dimensional figure, such as a line or arc, with an origin and orientation and such that its points are in one-to-one correspondence with a set of numbers; an axis forms part of the basis of a space or is used to position and locate data in a graph (a coordinate axis)
4. (anatomy) The second cervical vertebra of the spine

   Synonym: epistropheus

5. (anatomy) An imaginary, visualized plane separating two morphologically similar parts of an organism
6. (psychiatry) A form of classification and descriptions of mental disorders or disabilities used in manuals such as the DSM (Diagnostic and Statistical Manual of Mental Disorders)
7. (botany) The main stem or central part about which organs or plant parts such as branches are arranged
8. (military) An alliance or coalition.

   Synonyms: pact, compact, league

   • 1936, November 1st, Benito Mussolini, Milan Speech:

     This Berlin-Rome vertical line is not an obstacle but rather an axis around which can revolve all those European states with a will to collaboration and peace.

9. (figurative) The centre of attention within a process (e.g. the axis of investigation)

• (cervical vertebra): atlas

From Latin, name of an Indian animal mentioned by the Roman senator Pliny.

axis (plural axises)

1. A deer native to Asia, of species Axis axis.

   Synonyms: chital, cheetal, chital deer, spotted deer, axis deer

• Chital on Wikipedia.Wikipedia
• Axis axis on Wikispecies.Wikispecies

(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.)

• IPA^(key): /ak.si/

axis m (invariable)

1. synonym of cerf axis (“chital”)

• “axis”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012

From Proto-Italic *aksis, from Proto-Indo-European *h₂eḱs-i-s, from *h₂eḱs- (“axis, axle”); see also Lithuanian ašis (“axle”), Russian ось (osʹ), Sanskrit अक्ष (ákṣa, “axis, axle, balance beam”), Ancient Greek ἄξων (áxōn, “axle”), Old High German ahsa (“axle”), Icelandic eax, öxull, öksull, Old English eaxl (whence English axle). Compare also Etruscan 𐌀𐌂𐌔𐌉 (Acsi, “the Axia gens”).

• (Classical Latin) IPA^(key): [ˈak.sɪs]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈak.sis]

axis m (genitive axis); third declension

1. An axletree of wagon, car, chariot.
2. The North Pole.
3. The heavens or a region or clime of these.
4. A board, plank.

Third-declension noun (i-stem).

• “axis”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “axis”, in Charlton T. Lewis (1891), An Elementary Latin Dictionary, New York: Harper & Brothers
• "axis", in Charles du Fresne du Cange, Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• “axis”, in Gaffiot, Félix (1934), Dictionnaire illustré latin-français, Hachette.
• Carl Meißner; Henry William Auden (1894), Latin Phrase-Book‎^[2], London: Macmillan and Co.
  • the pole: vertex caeli, axis caeli, cardo caeli
    
• “axis”, in Harry Thurston Peck, editor (1898), Harper’s Dictionary of Classical Antiquities, New York: Harper & Brothers
• “axis”, in William Smith et al., editor (1890), A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin
• Langenscheidt Pocket Latin Dictionary

Borrowed from Latin axis. Doublet of eje.

• IPA^(key): /ˈaɡsis/ [ˈaɣ̞.sis]
• Rhymes: -aɡsis
• Syllabification: a‧xis

axis m (plural axis)

1. (anatomy) axis (vertebra)

• “axis”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025