noun

1. a diffusing or being diffused; specif.,
   1. a dissemination, as of news
   2. a scattering of light rays, as by reflection; also, the dispersion and softening of light, as by passage through frosted glass
   3. an intermingling of the molecules of liquids, gases, etc.
2. wordiness; diffuseness
3. Anthrop. the spread of a cultural or technological practice or innovation from one region or people to another, as by trade or conquest

Etymology: ME diffusioun < L diffusio