gravity
The fluid in a level is typically called a "spirit" or "spirit level fluid." It is usually a colored liquid, often dyed alcohol or mineral spirits, that is contained in a sealed vial with a bubble. This bubble indicates the level by showing whether a surface is horizontal or vertical when it is centered between the marked lines.
The straight level line is said to be horizontal.
level
A synonym for horizontal is level or laying flat.
Level is a palindrome that is a synonym for horizontal
The best tool to check for horizontal trueness is a spirit level or a laser level. These tools can help you determine if a surface is level or if there are any deviations from the horizontal plane.
If the bubble is exactly centered the level is horizontal (or vertical if it is one of those)
LEVEL
the word horizontal means: flat or level: a horizontal position. "The line is horizontal to the ground" would work.....
The horizontal level is called the horizon.
level
level