When someone has nous, they have a good mind for real-life problems: they can see what will work and what will not. It is not the same as book learning. A person can know many facts and still have little nous; another person may not have studied much, but they make wise, practical choices. People use this word mainly in British English. It sounds a little clever and a little old-fashioned — the kind of word a teacher or a newspaper might use: “She had the nous to leave before the trouble started.” In philosophy, the same spelling points back to an old Greek idea of “mind”, but everyday English almost always means practical good sense. Though actually, even there it is a bit fancy; many people would just say “common sense” or “good judgment”. British speakers usually say it to rhyme with “house”; the Greek-philosophy reading “noose” is a different habit.