horizontal

adjective

hor·​i·​zon·​tal ˌhȯr-ə-ˈzän-tᵊl 

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

ˌhȯr-ə-ˌzän-ˈta-lə-tē 

ˌhär-

noun

horizontally

ˌhȯr-ə-ˈzän-tᵊl-ē 

ˌhär-

adverb

Examples of horizontal in a Sentence

Recent Examples on the Web

During the event, two heliostats with moveable mirrors were used to direct images of the eclipsed Sun into a pair of horizontal telescopes. —Rebecca Boyle, TIME, 8 Apr. 2024

Previously, clicking on a video in the Facebook app may have pulled up a horizontal video, or one that played in a Feed-like player. —Bailey Schulz, USA TODAY, 3 Apr. 2024

Reducing Bathroom Fall Risks Walter’s advice for preventing bathroom falls included non-slip tile, assist bars (both horizontal and vertical) in and around showers, plus assist bars that double as towel bars. —Jamie Gold, Forbes, 29 Mar. 2024

Still swirling in a horizontal magnetic field, the muons would ionize atoms in the material, dissipating energy and quelling their buzzing about. —Byadrian Cho, science.org, 28 Mar. 2024

There is substantial horizontal break of around 10 to 15 inches. —Jaylon Thompson, Kansas City Star, 27 Mar. 2024

The new radiator grille features four horizontal louvres, the front and rear bumpers have been redesigned, the A-pillar has new cladding, and the front of the roof is now outfitted with a lip spoiler. —Bryan Hood, Robb Report, 26 Mar. 2024

The central truss was made up of three horizontal stretches, known as spans, with two sets of supports holding these above the water. —Chris Baraniuk, WIRED, 26 Mar. 2024

When driving, rear visibility is afforded by a temporary rearview mirror that attaches to the nearly horizontal windshield. —Peter Valdes-Dapena, CNN, 16 Mar. 2024

Word History

Etymology

see horizon

First Known Use

1555, in the meaning defined at sense 1a

Phrases Containing horizontal

• horizontal bar

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- 

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

-ᵊl-ē 

adverb

Legal Definition

horizontal

adjective

hor·​i·​zon·​tal ˌhȯr-ə-ˈzän-təl, ˌhär- 

: relating to, directed toward, or consisting of individuals or entities of similar status or on the same level

horizontally adverb