རང་འཐག

The etymology of rang ’thag (“mill” or “water-mill”) seems obvious. One just have to come to think of it. So rang ’thag is “something that grinds (’thag) (e.g. grains) on its own (rang) or naturally/automatically,” that is, even it happens to be a pair grinding stones that are operated manually. The rule that “etymologies have  no pervasion” (sgra bshad pa la khyab pa med) holds true here as well. So if there are some incorrigible rTog-ge-bas (“sophists”) out there, please don’t come up with the following argument:

rang ’thag chos can | rang bzhin gyis ’khor zhing (gro la sogs pa) ’thag pa ma yin par thal | gzhan (chu dang skyes bu’i ’bad rtsal) gyis (bskor zhing) ’thag pa’i phyir ||