Ne pas valoir tripette

Literally: Not to be worth a little tripe

Example: “Son dernier roman ne vaut pas tripette.” — His latest novel isn't worth a hill of beans.

English equivalent: Not worth a hill of beans

Origin: Words beginning in tri- usually promise three of something — tricycle, triangle — and this one promises nothing of the kind. A tripette is a small tripe, the animal gut that French cooking treats with more respect than most cuisines manage. So the phrase ought to mean that the thing in question is worth less than a scrap of offal, and it may well have started there: a piece of tripe too small to be worth dropping in the pot is about as close to nothing as food gets. But the Dictionnaire de Trévoux records an 18th-century verb triper, to trample underfoot and so, by extension, to hold in contempt — and since we assign little value to what we despise, tripette may have reached worthlessness by that road instead, with the gut a coincidence. Either way the verdict is the same and the tripe comes off badly.