As a Noun: 1. The spreading out of information or ideas or the spreading out of the affects of information and ideas to more and more people. English = spread. Formal English = dissemination. As a Verb or Adjective: 1. For something to gradually reach or affect a larger and larger area or more and more people. English = spread. 2. Of a number of things, to be located everywhere and far apart. English = (be) spread out. 3. Of information or ideas, to reach or affect or be distributed to many people. Formal English = disseminate.