(1) Four realms of Brahma gods on the plane of ethereal forms (form realm). (2) A synonym for the four immeasurable attitudes. Just as the gods in the first Brahma abode have immeasurable love, those in the second, immeasurable compassion, those in the third, immeasurable joy. and those in the fourth, immeasurable equanimity; similarly, practitioners of the first level of mental stability (first dhyana) have absorbed concentration on immeasurable love, practitioners of the second level have it on immeasurable compassion, the third on immeasurable joy and the fourth on immeasurable equanimity.
Tibetan: ཚངས་གནས་བཞི། tshangs-gnas bzhi