In a horizontal direction or position.

A horizontal component of a structure. / (geology) Horizon. / A Tasmanian shrub or small tree whose main trunk tends to lean over and grow horizontally, Anodopetalum biglandulosum

Perpendicular to the vertical; parallel to the plane of the horizon; level, flat. / (marketing) Relating to horizontal markets / (archaic) Pertaining to the horizon.

The property of being horizontal.

horizontalness

plural of horizontality

(transitive) To orient horizontally. / (euphemistic) kill, assassinate, execute / (transitive, marketing) To adapt to a horizontal market.

present participle of horizontalize

The act or process of horizontalizing.

Third-person singular simple present indicative form of horizontalize