sikkhamat

The ‘training mothers’, being the name for Thai Buddhist women who although not ordained as nuns embrace elements of the monastic lifestyle, such as celibacy. They have counterparts in other Theravāda countries, such as the dasa silmātā of Sri Lanka and the thilashin of Burma.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)