- vertical
- perpendicular
- orientation
- diagonal
- vertically
- transverse
- lateral
- radial
- flat
- level
- curved
- parallel
- linear
- angular
- concave
- geometric
- inverted
- axial
- crosswise
- swimming
- smooth
- naiant
- dihedral
- surface
- horizon
- horizontally
- spacing
- antiparallel
- rectangular
- width
- angle
- rectangle
- thickness
- cantilever
- conical
- lattice
- longitudinal
- directional
- planar
- spherical
- elongated
- diameter
- circular
- cylindrical
- beam
- widths
- surfaces
- spaced
- alternating
- scales
- oblique angle
- dots
- configuration
- ridges
- diameters
- pattern
- angles
- length
- curves
- curve
- frames
- propeller
- loops
- turret
- beams
- fuselage
- shapes
- tail
- shaft
- velocity
- stationary
- bending
- narrow
- magnetic
- frame
- flaps
- mirrors
- descending
- tapered
- loop
- stabilizers
- rear
- shaped
- layers
- configurations
- stripes
- cylinders
- grooves
- lines
- shafts
- fitted
- arc
- inch
- axis
- concentric
- axle
- zigzag
- arcs
- crankshaft
- strings
- elastic
- knot
- rudder
- cylinder
- helical
- tailplane
- propellers
- blade
- stabiliser
- outer
- cross-section
- gradient
- altitude
- flatterer
- stratigraphic
- stabilizer
- plani
- perforated
- plateau
- aslant
- shear
- flatling
- shallower
- plain
- flattery
- deplanate
- proximal
- flatness
- levelism
- symmetrical
- levelly
- monotone
- equalize
- homaloidal
- bilevel
- atilt
- raze
- plane
- evendown
- adulate
- blandishment
- supine
- aflat
- slant
- uneven
- libella
- tundra
- flatscape
- smoothly
- sidelong
- isoclinal
- ramp
- plainness
- unerect
- flatten
- subjacent
- evenness
- equally
- fawn
- evenly
- steppe
- unadorned
- smoothness
- even
- een
- metalevel
- eventide
- straight
- dirigent
- unequal
- incline
- tangent
- equidistant
- slope
- rampant
- coulisse
- spandrel
- plainly
- layer
- oblique
- mansard
- straightforward
- hogbacked
- hyperplane
- sine
- inclination
- aquaplane
- sycophant
- inclined
- tilt
- arcuate
- interplane
- chamfered
- orthogonal
- conic
- latitudinal
- curvilinear
- extensional
- lowermost
- caudal
- beveled
- kinematic
- convex
- anisotropic
- simple
- laminar
- collinear
- sagittal
- lamellar
- transversal
- isotropic
- tarsal
- sawtooth
- ellipsoidal
- circularly
- ogee
- equilateral
- corbel
- elliptic
- spline
- clinometer
- upright
- stoop
- straightness
- equal
- uninteresting
- lowerarchy
- hangar
- jointer
- height
- flatlock
- secant
- planation
- monotonous
- subsurface
- recumbent
- peneplain
- sideling
- eveninger
- spirit level
- flatlet
- e'en
- eveningness
- flatleaf
- lippage
- evenward
- crepidoma
- flet
- slopingly
- lowbie
- directrix
- binormal
- nonequal
- even keel
- uncurved
- slopingness
- equ
- yesterevening
- breadline
- aggrade
- upslope
- surficial
- intertie
- inclinometer
- sigmoidal
- azimuthal
- pronated
- anticlinal
- synclinal
- sideward
- reeded
- tieback
- interocular
- norite
- gradational
- radiolucent
- pelite
- turonian
- clastic
- conglomeratic
- collimated
- positionable
- dextral
- angulated
- acromion
- rotatable
- pelitic
- knurled
- tensional
- crosshatch
- arcsecond
- countersunk
- amphibolite
- lithological
- winglike
- coplanar
- triadic
- unitized
- mesial
- stippled
- gimbaled
- flexural
- two dimensionality
- isostatic
- strickle
- bitangent
- flatform
- yestereve
- tormenter
- gradian
- underlie
- regularize
- delayer
- coequal
- overside
- subnormal
- flatmate
- orbiform
- butter up
- as level
- picture plane
- even up
- probability paper
- orbital plane
- rock bottom
- pedal curve
- mansard roof
- mise en scene
- change surface
- plane angle
- even steven
- cartesian plane
- jack plane
- projective plane
- great circle
- this even
- high water mark
- suck up
- salt flat
- horizontal surface
- contour line
- before night
- angle of incidence
- of even date
- elliptic curve
- spherical angle
- latus rectum
- above board
- lap joint
- y level
- equilateral triangle
- simple harmonic motion
- plumb bob
- isosceles triangle
- counterclockwise rotation
- satin stitch
- even out
- grade on curve
- pancake land
- two dimensional
- structural member
- euclidean space
- land topographical feature
- even money
- on line
- land on runway
- diagonally
- horizontal
- contour
- laterally
- perforations
- horizontal wells
- geometry
- swivel
- widely spaced
- intersecting
- sill
- azimuth
- geometrical
- tubular
- curvature
- footwall
- porosity
- horizontal drilling
- fig.
- contoured
- topographic
- overlying
- volumetric
- cantilevered
- elliptical
- spindle
- drilled
- hexagonal
- angled
- flange
- ft
- downhole
- l shaped
- sloped
- ft.
- triangles
- amplitude
- wellbore
- asymmetrical
- distal
- thicknesses
- infill drilling
- wavy
- basal
- rectangles
- casing
- elongate
- gradients
- frac
- drill holes
- outwards
- aft
- shallow
- sidewall
- blocky
- resistivity

That's about all the horizontal related words we've got! I hope this list of horizontal terms was useful to you in some way or another. The words down here at the bottom of the list will be in some way associated with horizontal, but perhaps tenuously (if you've currenly got it sorted by relevance, that is). If you have any feedback for the site, please post it here, but please note this is only a hobby project, so I may not be able to make regular updates to the site. Have a nice day! 🐔