Spirit level

/spˈɪɹɪt lˈɛvəl/

[noun]

Spirit level

[NOUN]

a tool consisting of a vial filled with liquid and an air bubble used to determine horizontal or vertical alignment

synonyms : bubble level

Examples

1. The authors of The Spirit Level, present a persuasive case that more equitable societies are healthier, have longer life expectancies, experience less crime, and in security.

2. This is from a book called The Spirit Level, and what the author has tried to do there was correlate the inequality in a given society with the level of mental illnesses in those societies.