If you're asking what DMOZ would stand for if DMOZ were an acronym, well, technically it's not an acronym. It comes about because in the early days the directory existed at
http://directory.mozilla.org (in fact, you'll notice that that URL still mirrors dmoz.org). When they decided to give the directory its own domain, they just took the "d" from directory and "moz" from mozilla and came up with dmoz.org.
But it doesn't really mean anything.
If you're asking something else, well, I don't know what you're asking then so you'll have to clarify.