tilt [ME] In its earliest sense, around 1300, tilt meant ‘to fall, topple’, and a jousting knight who tilted at a mounted opponent by riding with a lance levelled at his body was trying to knock him off his horse. This image of two armoured figures galloping towards each other is the source of at full tilt [L16th], ‘with maximum energy or force’. In the mock-heroic novel Don Quixote (1605–15) by Miguel de Cervantes, the hero Don Quixote sees a line of windmills on the horizons and takes them for giants, which he attacks. This gave us the expression tilt at windmills [M17th]. See also spanish words.