horizontal

The word “horizontal” means level and flat; parallel to the ground rather than upright. In plain terms, lying flat or level, as opposed to vertical (upright).

“Horizontal” is pronounced ho-rih-ZON-tuhl (/ˌhoɹəˈzɑn.təl/ in IPA).

Here is “horizontal” used in a sentence: “Lay the shelf horizontal before drilling the holes.”

The opposite of “horizontal” — its antonyms — is vertical.

Depending on how it is used, “horizontal” can be an adjective and a noun.

The word “horizontal” comes from French. From French horizontal, from horizon (see "horizon").

“Horizontal” is a fairly common word in modern English.

“Horizontal” has 2 distinct senses listed in this dictionary. The most common is: level and flat; parallel to the ground rather than upright.

Horizontal describes something level and flat, running parallel to the ground or the horizon, such as a tabletop or a shelf. Vertical describes something upright, running straight up and down at a right angle to the ground, such as a wall or a flagpole.

Horizontal shares its root with "horizon," the flat line where land or sea meets the sky, so horizontal always means level and side-to-side. Vertical, by contrast, points straight up and down like a standing person.

Horizontal frequently pairs with words such as line, surface, plane, axis, position, and stripes. In business, a "horizontal" merger or market describes companies operating at the same level of an industry rather than in a supplier-to-customer relationship.

Beyond describing physical flatness, horizontal is used in organisations and design to mean spread across one level rather than ranked in a hierarchy. A "horizontal structure," for example, has few layers of management.