ax·​is | \ ˈak-səs How to pronounce axis (audio) \
plural axes\ ˈak-​ˌsēz How to pronounce axes (audio) \

Definition of axis

 (Entry 1 of 2)

1a : a straight line about which a body or a geometric figure rotates or may be supposed to rotate the Earth's axis
b : a straight line with respect to which a body or figure is symmetrical the axis of a cone

called also axis of symmetry

c : a straight line that bisects at right angles a system of parallel chords of a curve and divides the curve into two symmetrical parts
d : one of the reference lines of a coordinate system (see coordinate entry 3 sense 1a)
2 anatomy
a : the second vertebra of the neck on which the head and first vertebra turn as on a pivot
b : any of various central, fundamental, or axial parts
3 botany : a plant stem
4 crystallography : one of several imaginary lines assumed in describing the positions of the planes by which a crystal is bounded and the positions of atoms in the structure of the crystal
5 : a main line of direction, motion, growth, or extension the axis of a city
6a : an implied line in painting or sculpture through a composition to which elements in the composition are referred fruit and flowers arranged about a diagonal axis
b : a line actually drawn and used as the basis of measurements in an architectural or other working drawing
7 aviation : any of three fixed lines of reference in an aircraft that run in the longitudinal, lateral, and vertical directions, are mutually perpendicular, and usually pass through the aircraft's center of gravity
8 : partnership, alliance an axis of countries
9 : a point or continuum on which something centers an axis of social power

Definition of Axis (Entry 2 of 2)

: of or relating to the three powers Germany, Italy, and Japan engaged against the Allied nations in World War II

Keep scrolling for more

Examples of axis in a Sentence

Noun the Earth's axis of rotation the spin of the Earth on its axis
Recent Examples on the Web: Noun The x-axis is still just the unalterable fact of time. Rafil Kroll-zaidi, Harper's Magazine, "Reason Not the Need," 15 Sep. 2020 Hurricane #Sally Forecast Changes: The axis of heaviest rainfall has shifted to the east along with the eastward adjustments in Sally's forecast track. Leigh Morgan, al, "Hurricane Sally: ‘Historic’ flooding expected as Category 1 storm heads for Alabama at a crawl," 15 Sep. 2020 Much of the lengthy I-95 corridor had a similar setup for potential flash flooding: deep tropical moisture, a convergent axis of wind near the surface, enough instability to generate convective storms, and a weak upper level disturbance. Jason Samenow, Washington Post, "How Thursday’s flood unfolded in the Washington region and why it was so hard to forecast," 11 Sep. 2020 Understanding factors such as volcanic activity, possible shifts in the earth’s rotational axis and solar activity could help keep current events in perspective and inform the debate about the path forward. Smithsonian Magazine, "Readers Respond to the January/February Issue," 10 Mar. 2020 The principal axis leads from less important to more important spaces, to come to rest at some ultimate point of repose. Michael J. Lewis, National Review, "The Death of Public Beauty," 3 Sep. 2020 The improvement of those two teams can greatly swing the axis of just how potent SMU’s nonconference schedule truly is this season. Sam Blum, Dallas News, "5 takeaways from SMU’s nonconference basketball schedule: Mustangs’ slate features 2 huge fish, plenty of home games," 20 Aug. 2020 The basketball part of DeRozan’s world, at least, could be returned upright on its axis. Jeff Mcdonald,, "Playoffs still possible, but Spurs have already won," 12 Aug. 2020 My littlest whirling dervish tilted on his axis for a few more rotations, before collapsing in a sweaty heap next to me on the grass. Sarah Evans, Longreads, "Addiction’s Seismic Effects on a Family," 10 Aug. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'axis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of axis


14th century, in the meaning defined at sense 1a


1938, in the meaning defined above

History and Etymology for axis


Latin, axis, axle; akin to Old English eax axis, axle, Greek axōn, Lithuanian ašis, Sanskrit akṣaḥ

Keep scrolling for more

Learn More about axis

Time Traveler for axis

Time Traveler

The first known use of axis was in the 14th century

See more words from the same century

Statistics for axis

Last Updated

18 Sep 2020

Cite this Entry

“Axis.” Dictionary, Merriam-Webster, Accessed 26 Sep. 2020.

Keep scrolling for more

More Definitions for axis


How to pronounce Axis (audio)

English Language Learners Definition of axis

: the imaginary straight line that something (such as the Earth) turns around
: a straight line that divides a shape evenly into two parts


ax·​is | \ ˈak-səs How to pronounce axis (audio) \
plural axes\ ˈak-​ˌsēz \

Kids Definition of axis

1 : a straight line about which a body or a geometric figure rotates or may be thought of as rotating the earth's axis
2 : a line of reference used to assign numbers to locations in a geometric plane


ax·​is | \ ˈak-səs How to pronounce axis (audio) \
plural axes\ -​ˌsēz How to pronounce axes (audio) \

Medical Definition of axis

1a : a straight line about which a body or a geometric figure rotates or may be thought of as rotating
b : a straight line with respect to which a body, organ, or figure is symmetrical
2a : the second vertebra of the neck of the higher vertebrates that is prolonged anteriorly within the foramen of the first vertebra and united with the dens which serves as a pivot for the atlas and head to turn upon

called also epistropheus

b : any of various central, fundamental, or axial parts the cerebrospinal axis the skeletal axis
c : axilla

Keep scrolling for more

Comments on axis

What made you want to look up axis? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Challenging Vocabulary Quiz Returns!

  • stylized drawing of woman pole vaulting across gap to get trophy
  • Which is a synonym of fuliginous?
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!