The quality of letting light pass through while not letting you see clearly through to the other side. It is the noun for 'translucent'. Frosted bathroom glass has translucence: light comes in, but the shapes beyond are only blurred outlines. So do jade, thin porcelain, wax, a paper lantern, a young leaf held up to the sun. The word is uncountable and quite formal — it belongs to writing about art, design, materials and nature, and it often appears when the writer admires something: 'the translucence of the jade', 'the strange translucence of her skin'. That last use, about skin, is common in novels and usually suggests either great delicacy and beauty or, sometimes, illness — someone so pale you feel you could almost see the light through them. There is a second noun, 'translucency', which means the same thing. In practice 'translucency' turns up more often in technical and scientific writing (measuring the translucency of a material), while 'translucence' sounds more literary. Neither is wrong. In ordinary conversation people simply do not use either one; they say 'you can see the light through it'.

半透明（透光但看不清後面的東西）