[hawr-uh-zon-tl, hor-]
  1. at right angles to the vertical; parallel to level ground.
  2. flat or level: a horizontal position.
  3. being in a prone or supine position; recumbent: His bad back has kept him horizontal for a week.
  4. near, on, or parallel to the horizon.
  5. of or relating to the horizon.
  6. measured or contained in a plane parallel to the horizon: a horizontal distance.
  7. (of material on a printed page, pieces on a game board, etc.) extending across, from the left to the right of the viewer.
  8. of or relating to a position or individual of similar status: He received a horizontal promotion to a different department, retaining his old salary and title.
  9. Economics. of or relating to companies, affiliates, divisions, etc., that perform the same or similar functions or produce the same or similar products: Through horizontal mergers the company monopolized its field.
  1. anything horizontal, as a plane, direction, or object.

Origin of horizontal

1545–55; < Latin horizont- (stem of horizōn) horizon + -al1
Related formshor·i·zon·tal·i·ty [hawr-i-zon-tal-i-tee, hor-] /ˌhɔr ɪ zɒnˈtæl ɪ ti, ˌhɒr-/, hor·i·zon·tal·ness, nounhor·i·zon·tal·ly, adverbsub·hor·i·zon·tal, adjectivesub·hor·i·zon·tal·ly, adverbsub·hor·i·zon·tal·ness, nounun·hor·i·zon·tal, adjectiveun·hor·i·zon·tal·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for horizontality

Historical Examples of horizontality

British Dictionary definitions for horizontality


  1. parallel to the plane of the horizon; level; flatCompare vertical (def. 1)
  2. of or relating to the horizon
  3. measured or contained in a plane parallel to that of the horizon
  4. applied uniformly or equally to all members of a group
  5. economics relating to identical stages of commercial activityhorizontal integration
  1. a horizontal plane, position, line, etc
Derived Formshorizontality or horizontalness, nounhorizontally, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for horizontality



1550s, "relating to or near the horizon," from French horizontal, from Latin horizontem (see horizon). Meaning "flat" (i.e., "parallel to the horizon") is from 1630s. Related: horizontally.

Online Etymology Dictionary, © 2010 Douglas Harper