IT’S no surprise that in recent years some on the left have embraced the term “progressive” as a substitute for “liberal.” The right has so demonized “the L-word” that during a Democratic debate in 2007, Hillary Clinton, asked by a voter whether she was a liberal, said that she preferred to identify herself as  of course  a “modern progressive.”

But she doesn’t have as much company as you might expect: a recent USA Today/Gallup poll found that only one in four liberals would go by the label “progressive,” while 17 percent rejected the term and 57 percent were “unsure.” Even stranger, 7 percent of conservatives considered themselves progressives, and nearly half said they were unsure if the label applied to them.

Why is America so unclear on what progressive means as a political position? “Progress,” it would seem, is pretty meat-and-potatoes as words go  moving ahead, we assume. Shouldn’t it be clear who is committed to moving ahead?

Part of the problem with “progressive” comes from the bastard nature of English vocabulary. We know what transgress, aggressive and progress mean. But if someone asked us, “Gress much?” we’d draw a blank. Gress, like “mit” in transmit, isn’t a word. Gress comes from Latin gradus, for “go,” and thus “progress” breaks down as “forward-go.” Or at least it did to an Ancient Roman. Latinate words’ meanings are often less immediately precise to us than those from English’s original Anglo-Saxon rootstock. If our word for progressive were something like “go-forward-ive,” Gallup pollsters would find people less ambivalent.