Your statement is an oxymoron and demonstrates that you don't really understand the word "euthanasia":
Evidently euthanasia proponents like Judge Greer prefer that Terri's death be as grisly as possible so they can convince "the people" to make legal their preferred policy of offing those of us they consider unworthy of life or simply too costly to keep alive by other more "humane" means.
I believe you are wrong, however, in that the supporters of starving and dehydrating Terri to death are consistently describing this process as painless and gentle and profess to be doing the caring and humane thing by denying her food and water, even by mouth. So in that case, they themselves would describe what is going on as "euthanasia".