To people who aren't familiar with these programs, "clay render" is most readily interpreted as "rendered in clay", meaning "made from clay". "Rendering" isn't a term unique to the digital media, afterall. Hence the confusion, which I suspect your comment didn't clear up for the person.
thank for your explanation , but people can see the category of art below. Why I think "Digital Art / 3-Dimension Art" + my comment " clay render " is enough? because his comment show me that he knows Zbrush. So I think it's clear for this man. thank again for your great explaination to people who aren't familiar with these programs and read comment and my reply.