bum can

བུམ་ཅན
lit. "flask-like" or "flask-shaped"; refers to a particular breathing technique known as flask-breathing during which ones belly is filled with air so as to take on the shape of the round part of a flask or vase; applied in advanced vajrayana practices dealing with the subtle channels (rtsa) and winds (rlung) of ones body, most commonly associated with the practice of inner heat or gtum mo; a proper flask-breathing sequence is always to be practiced with the four accompanying exercises of inhaling, filling, releasing and shooting (like an arrow); before attempting the practice of bum can, it would ususally be preceded by two gentler versions of it, the 'jam rlung and bar rlung or gentle breathing and intermediate breathing [TSD]

kumbhaka, tree, vase-like manner , hold in kumbhaka [JV]

pot-belly; a pot-belly; vase-shaped [breathing]. srog rtsol bum can nyams len practice holding the life force in a vaselike manner, vaselike manner [RY]

vase-breathing [Belly is like a vase, pranas are held down and up] [IW]

vase-breathing [IW]