What is the definition of homogeneous?

It means all is the same. For example, long before you were born, milk was not homogenized. After pasteurizing it, it was bottled, and the cream would separate out, and sit on top of the milk. To homogenize it (make every drop the same as every other drop) they blended it at very high speeds so that the cream was consistently and evenly mixed in with the milk. The cream is not disolved, it is floating around in there in tiny little pieces, therefore is called a colloidl suspension. In theory, eventually the cream would rise to the top again, but the milk would spoil long before that happened.

Adjective

Definition:

Of same kind: having the same kind of constituent elements, or being similar in nature

For example, a group of students could be put together homogeneously by age (all 5 year olds, sex (all girls), or math ability (all algebra 1 students). Mixing them (putting 5th, 6th, and 7th graders together, for example) would be heterogeneous.