Chato de galochas is an idiomatic expression of the Portuguese language and means someone extremely boring or with socially unpleasant behavior. It is the case of a special boring, a upgrade from the usual boring.
Example:
My day was going well until that bore in wellies showed up.
expression source
The expression "boring galoshes", very popular in Brazil, came about thanks to the galoshes. A galoshe is an accessory that is put on over the shoe, preventing it from being damaged by water. Wellies were widely used in the 50s and 60s in the interior of Brazil, where in many places there were still no sidewalks. However, even today, some professions require wellies-style footwear.
Some authors believe that a "wellies bore" is a resistant borer, characteristic of the wellies themselves. Thus, even with adverse weather conditions, the boring wore his wellies to annoy other people. Oftentimes, the boring one entered the house of people in wellies, wetting and dirtying the whole house of the host, who was certainly displeased with such a display of disregard. These days, boring wellies are not necessarily wearing wellies, but the expression is still used to describe people with unpleasant attitudes.
