Spirit level
A tool that shows whether a surface is even — a simple instrument for telling true from almost-true.
A spirit level in a dream is the dream's image of a simple instrument for telling true from almost-true. The level does not argue; the bubble settles where the bubble settles. The dream brings the level when something in your life — a moral judgement, a practical construction, a sense of fairness in an arrangement — is being checked against an honest reference. A level showing the bubble exactly centred is the dream affirming that what is being built is straight. A level showing the bubble far off, with the surface still being treated as if it were even, is the dream noting that the honest measurement has been made and is being ignored.