A diffuse mass of interstellar dust or gas or both, visible as luminous patches or areas of darkness depending on the way the mass absorbs or reflects incident radiation.
星云星际空间的尘埃或气体或两者共同构成的巨大天体，由其对光线的吸收和反射来决定其明亮可见或黑暗一团
Fashion trends diffuse themselves rapidly around the globe.
时装新潮很快就在全世界流行起来。
The light was diffused by the leaves.
树叶使光线漫射。
