Homogeneous means (1) of the same or similar nature, and (2) uniform in structure or composition. Its corresponding noun is homogeneity. Homogenous, whose corresponding noun is homogeny, is a biological term meaning similar in structure between organs or parts.
Homogenous and homogeneous are separate words with different definitions, but widespread confusion has made them more or less interchangeable in real-world usage. Still, careful writers distinguish between them. And most never have reason to use homogenous because its applications are so esoteric.
Examples
These writers use homogeneous well:
The Arab world is not at all homogeneous and responses to unrest will play out very differently in each country … [Telegraph]
Complex fluids can be considered homogeneous at the macroscopic (or bulk) scale … [Physics]
But unlike the homogeneous Apple iPhones, there are many different flavors of Droid. [GCN]
Finding examples of homogenous used in its traditional sense is almost impossible. Searching the web, we mostly find examples like these:
Kiss Each Other Clean is much more focused and homogenous, but there’s still a lingering sense of abundant inspiration, eager to carry the songs off to different lairs. [The Independent]
Research has also proven that well-led diverse groups are better at problem solving and homogenous teams run the risk of “groupthink.” [Huffington Post]
After getting some flack for a rather homogenous cover of white actresses last year, Vanity Fair‘s new Hollywood issue is mixing things up. [Gawker]
(Incidentally, that last writer also uses flack in place of flak.)
