in a pinch

Example: “In a pinch, you can substitute yogurt for sour cream.”

Origin: The older British form, "at a pinch," is documented from 1489, in William Caxton's English translation of The Book of Faytes of Armes and of Chyualrye. "Pinch" itself, from Old North French pinchier, describes a firm, uncomfortable squeeze between finger and thumb, and the idiom borrows that physical sensation of being squeezed to describe circumstances that are similarly tight and constrained — a situation with little room to maneuver, forcing a substitute or compromise solution where a preferred option isn't available or isn't fast enough.