A Chinese tenet system introduced to Tibet by the Chinese monk Hoshang Mahayana in the eighth century. It asserts that it is impossible to gain liberation from samsara by using samsaric mental activity. One needs to make a total break from that level and break out "all of a sudden." The Tibetan term is a transcription of the Chinese term "dunmen, 顿门,頓門," (sudden gateway).
Tibetan: སྟོན་མིན། ston-min