n. Philosophy Reason and knowledge as opposed to sense perception.n. Philosophy The rational part of the individual human soul.n. Philosophy The principle of the cosmic mind or soul responsible for the rational order of the cosmos.n. Philosophy In Stoicism, the equivalent of Logos.n. Philosophy In Neo-Platonism, the image of the absolute good, containing the cosmos of intelligible beings.n. Chiefly British Good sense; shrewdness: "Hillela had the nous to take up with the General when he was on the up-and-up again” ( Nadine Gordimer).