horizontal (n.)
horizontal (adj.)
- direct
- earth
- even
- flat
- flattened
- floor
- flush
- ground
- level
- lineal
- linear
- plain
- plane
- prone
- rectilineal
- rectilinear
- right
- rolled
- smooth
- smoothened
- squashed
- straight
- streamlined
- supine
- table
- tabular
- trodden
- true
- unbending
- unbent
- unbowed
- unbroken
- uncurved
- undeviating
- undistorted
- uninterrupted
- unswerving
- unturned
- upright
- vertical
