sbu gu

སྦུ་གུ
hollow, cavity, pipe, tube, bushings, straw [IW]

hollow, cavity, pipe; a hole, tunnel [RY]

pipe, tube, hollow, cavity, narrow interior of anything, hollow stem, hollow reed, SA lbu ba, channel [JV]

1) interior channels, interior cavities; 2) pipe, tube; 3) hole, tunnel; 4) straw (for sucking); 5) hollow, interior of anything [Erick Tsiknopoulos]