What does the plumb repersent in Freemasonry?

Answer 1

The plumb measures verticals so it represents correctness of action. There is a line in the lecture of the Fellowcraft degree that states, "The speculative Mason examines every action of his life by the square of morality,...seeing that no violent propensity causes him to swerve from the plumb line of rectitude." There are many other references in the ritual to the plumb line being used to measure correctness of action, but that's the lecture I know best, so that's the line I know best.

Answer 2

same as a middle finger