isogloss

When I must explain to some Americans that by pop I mean soda, there’s a word for the line between the areas using the two words I so gloss: isogloss. It’s even pronounced like “I so gloss,” though it’s not taken from it. Quite reasonably for a scholarly term, it’s a Greek compound borrowed from German scholarship. People who study dialects will map out where people say see-saw and where they will say teeter-totter, for instance, and discernible (if in reality often fuzzy and permeable) boundaries can be drawn. Isoglosses can criss-cross and defeat what one expects from dialects. The word isogloss, for its part, has a certain sheen uncommon in the typically brutish, percussive, or convoluted classically based terminology of scholarship. It slips on the tongue like wet silver, with perhaps a sweetness like icing on a cupcake – or a glass of sherry. When we think of speech, this word’s echoes conjure the mouth speaking it, with gloss on the lips like ice (ah, Rocky Horror fans, do we have you now?). The gl here is not, however, the Germanic gl of gleam, glitter, and other shiny things – that’s the other gloss, a mere coincidence of form with this Greek-derived gloss, with the gl of the mouth, as in glottis. Nor is it akin to glace, French “ice.” There is also no ice in iso. The iso that catches your eye so quickly is not the lonely start of isolated (which is related to island) but the Greek “equal” we see in isotonic, isomorphic, and those isobars you see on weather maps (the bar from Greek for “pressure,” as in barometer, but no, not bar mitzvah, pressure or no). Think of isoglosses as linguistic isobars. And see them in action at www.popvssoda.com.