1. Uniform in composition or character. (wikipedia.org)
2. Of the same kind; alike, similar. (wiktionary.org)
3. Having the same composition throughout; of uniform make-up. (wiktionary.org)
4. (Chemistry) in the same state of matter. (wiktionary.org)
5. (Mathematics) Of which the properties of a smaller set apply to the whole; scalable. (wiktionary.org)
6. Consisting of or composed of similar elements or ingredients, of a uniform quality throughout. (biology-online.org)
Word origin: From Medieval Latin homogeneus, from Greek homogenes “of the same kind,” from homos “same” + genos “kind, gender, race, stock”. Earlier in this sense was homogeneal (c.1600).