It is when you get fucked by someone from Vermont

When you eat dirt for the first time and leave your family to build a shack in the woods

To pull out in front of other automobiles, usually in a hurried and hasty manner, in order to drive as slowly as possible. This usually occurs during what native Vermonters call "leaf-peeping" season when tourists (called flat-landers by natives) pull into a thoroughfare as though they were still in New Jersey, only to drive as though a New Jersey patrol car were following them, with lights, and guns drawn.

A more factual investigation, however, shows that Vermonters themselves far more commonly "Vermont" other drivers -- hence, being "Vermonted" while driving your pregnant, and in labor, wife to a hospital. The "Vermonting" car is usually at least ten years old, out of inspection. and can easily be recognized by the half-dozen to dozen cars following it. The "Vermonting" care does not obey speed limits, choosing to drive at least 10 to 15 miles below the said speed limit.