The meaning of Lie detector in dream | Dream interpretation
Dreams of a lie detector represent cynicism, doubt, and distrust. What you are looking for you are looking with, so if you are preoccupied with looking for lies to prove someone else’s guilt, you are exposing your own guilt and -judgment. Alternatively, this dream may indicate that you are using your powers of discernment to read between the lines and lies. Consider the feeling tone of this dream to discern the significance.
Symbolic of needing to be honest, Col. 3:9