noun

1. A horizontal component of a structure

2. Horizon

3. A Tasmanian shrub or small tree whose main trunk tends to lean over and grow horizontally, Anodopetalum biglandulosum

adjective

1. Perpendicular to the vertical; parallel to the plane of the horizon; level, flat

2. Relating to horizontal markets

3. Pertaining to the horizon

   “1667: As when the Sun new ris'n / Looks through the Horizontal misty Air — John Milton, Paradise Lost, Book 1, ll. 594-5”

Synonyms: linear, melodic