flatfoot

In 1899 the police officers of Akron, Ohio, climbed aboard the first police car (a patrol wagon powered by an electric motor). In that same year the noun flatty was first used in print with the meaning "police officer." Mere coincidence? Maybe, but consider that quite a few similar words have been used over the years to distinguish pedestrian officers from mobile ones, including flat, flat arch, flathead, flatter, and flatfoot. Other notable (and more comic) descriptors are pavement pounder and sidewalk snail. Flatfoot dates its "police officer" sense from 1913. It is especially used of those footing it to keep our cities safe, but it can also refer to police in general.