Making the Grade

I was reading some article (I can't remember which one) on Slate.com the other day and at the bottom of the page was a link to this article aboutsome guy who spent two weeks without a car, bicycling everywhere instead. Big deal, says I; I've never owned a car in my life. Maybe it's different in America.

Anyway, here's a paragraph from the piece:

As I approached the Kmart cash registers in this early visit, metal cleats clicking on the linoleum tile, the cashier girls stopped comparing their incarcerated boyfriends and stared. Then they looked away. One studied her nails, while the other concentrated on scanning the plunger and counting change. This, I'd come to recognize, was The Silence, the awkward, get-this-over-with tension that often accompanied transactions where one party is clad head-to-toe in stretch synthetics that might not smell so great. I paid, grabbed the plunger, and click-clacked out the automatic sliding doors, to everyone's relief. And as I pedaled away, I realized that bike clothes aren't merely ugly, to normal people: They're transgressive.

"Transgressive", I thought. "Hmmm." "Trans-" means "across", but where on earth does "-gressive" come from? "Progress", "ingress", "congress": what could they all have in common?

All "-gress" words (with the obvious exceptions of the feminine-ending "ogress" and "tigress"), it turns out, come from Latin "gradi", "to go", which led to "gradus", "walking". To transgress means to walk across the line separating decent behaviour from indecent; to make progress means to go forward; and so on and so on.

"Gradi" also looks like "grade", and sure enough, it's also the source of "-grade" words such as "retrograde" ("going backwards"), as well as "gradient", and "grade" in all its senses: a class, a slope, a rank, a level.