spirit level


Cars & Driving

  • noun a tool for testing if a surface is level (or vertical) using a glass tube containing an air bubble


  • A device used to set an instrument to true horizontal or true vertical, consisting of a glass tube nearly filled with liquid so a traveling air bubble is formed. Cheap levels are bent concave; better levels are ground internally to an overall concave shape.

Real Estate

  • noun a tool used for checking the horizontal or vertical alignment of something, typically with a tube containing liquid with a bubble in it, the position of the bubble being the indicator of alignment