horizontal

adjective

hor·​i·​zon·​tal ˌhȯr-ə-ˈzän-tᵊl How to pronounce horizontal (audio)
ˌhär-
1
a
: of or relating to the apparent junction of earth and sky : situated near the horizon
b
: parallel to, in the plane of, or operating in a plane parallel to the horizon or to a baseline : level
horizontal distance
a horizontal engine
2
: relating to, directed toward, or consisting of individuals or entities of similar status or on the same level
horizontal mergers
horizontal hostility
3
medical : relating to or being transmission (as of a disease) by physical contact or proximity in contrast with inheritance
Genes are normally inherited from parents, but they can also be inserted into a genome by viruses, plasmids, and other foreign agents—a phenomenon called horizontal transfer.Stephan Reebs
compare vertical sense 4
horizontal noun
horizontality noun
horizontally adverb

Examples of horizontal in a Sentence

Recent Examples on the Web
These examples are automatically compiled from online sources to illustrate current usage. Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Thus, a recent study set out to investigate the horizontal and vertical movements of megamouth sharks in the northwest Pacific, focusing on waters off the coast of Taiwan. Melissa Cristina Marquez, Forbes, 31 Oct. 2024 Many come with or without backgrounds and in a horizontal or vertical format to suit your setup. Simon Hill, WIRED, 30 Oct. 2024 Make a horizontal cut into the breast just above each wing, and cut entire breast portion free. Jeanne Ambrose, Better Homes & Gardens, 29 Oct. 2024 The autofocus delivered a suitably crisp image in my tests, while the horizontal and vertical keystone adjustments didn't always work well. PCMAG, 27 Oct. 2024 See all Example Sentences for horizontal 

Word History

Etymology

see horizon

First Known Use

1555, in the meaning defined at sense 1a

Time Traveler
The first known use of horizontal was in 1555

Dictionary Entries Near horizontal

Cite this Entry

“Horizontal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/horizontal. Accessed 13 Nov. 2024.

Kids Definition

horizontal

1 of 2 adjective
hor·​i·​zon·​tal
ˌhȯr-ə-ˈzänt-ᵊl,
ˌhär-
1
: of or relating to the horizon
2
: parallel to the horizon : level
3
: being on the same level
horizontally
-ᵊl-ē
adverb

horizontal

2 of 2 noun
: a horizontal line or plane

Medical Definition

horizontal

adjective
hor·​i·​zon·​tal ˌhȯr-ə-ˈzänt-ᵊl, ˌhär- How to pronounce horizontal (audio)
1
: relating to or being a transverse plane or section of the body
2
a
: relating to or being transmission (as of a disease) by physical contact or proximity in contrast with inheritance compare vertical
b
: of or relating to horizontal gene transfer
horizontally adverb

Legal Definition

horizontal

adjective
hor·​i·​zon·​tal ˌhȯr-ə-ˈzän-təl, ˌhär- How to pronounce horizontal (audio)
: relating to, directed toward, or consisting of individuals or entities of similar status or on the same level
horizontally adverb
Last Updated: - Updated example sentences
Love words? Need even more definitions?

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