spirit level

noun, Surveying
1.
a device for determining true horizontal or vertical directions by the centering of a bubble in a slightly curved glass tube or tubes filled with alcohol or ether.
Also called level.
Origin
1760-70
Examples from the web for spirit level
  • We use spirit level surveys to measure elevation change.
  • Utilize plumb bob, gauge line and spirit level to obtain straight courses.
  • Verifies vertical alignment of posts with plumb bob or spirit level.
  • Included is a spirit level, adjustable leveling screws and a desiccator which can be readily inspected.
  • Side-to-side level may be adjusted by means of the built-in spirit level.
  • Check that the apparatus is in a true level condition with a spirit level placed on the top of the kettle.
  • If only vertical position were sought, the spirit level has been the instrument of choice.
  • Instruments were checked frequently with a spirit level to insure that they remained level.
British Dictionary definitions for spirit level

spirit level

noun
1.
a device for setting horizontal surfaces, consisting of an accurate block of material in which a sealed slightly curved tube partially filled with liquid is set so that the air bubble rests between two marks on the tube when the block is horizontal