Organdie is a kind of cotton cloth. It is very thin — you can almost see through it — but it feels stiff, not soft like a T-shirt. Dressmakers use it for light dresses, party skirts, and sometimes curtains, because it stands out a little instead of hanging heavy. The stiffness often comes from a finish put on the cloth; after a few washes it can go softer. The word is more British; in American English the same cloth is usually called organdy. You will hear it from people who sew or sell clothes, not in ordinary chat about what to wear tomorrow.

歐根紗（薄而硬的棉布；也有人說玻璃紗）