(derogatory) ~ sl.: euphemism for a person of mentally challenged status. Etymology: C20 - Derived from the stereotyped behaviour of mentally challenged people, observed to place their open mouths into prolongued contact with the external windows of public or private transport on which they are seated.
Usually a bulbous half witted individual, with several chins. Enjoys quality time on a Friday waiting for the yellow bus after lunch.
Enjoys sitting on the brightyellow bus, face pressed up against the glass, tongue hanging out cleaning the window. Sometimes heard mumbling Me Bart, or Im not being funny chap.