What does the expression "half a bubble off plumb" mean?

 

Frank Elliott

Writer

Answered August 19, 2016

In this instance, the bubble refers to those found in a liquid level (and actually, there is only one bubble). It's an example of small-town humor.

Therefore “half a bubble off plumb” would be ‘somewhat off level.’ It's a colorful expression for a folksy implication that they’re calling someone crazy or crooked, but only euphemistically, indirectly.

Small-town humor demands that one shouldn’t be too harsh or blunt because one can’t remain isolated from others in close proximity. So one must choose one's enemies very carefully, and being blunt about others is not being careful.