Bush, n. [D. bus a box, akin to E. box; or F. boucher to plug.] 1. (Mech.) A lining for a hole to make it smaller; a thimble or ring of metal or wood inserted in a plate or other part of machinery to receive the wear of a pivot or arbor. Knight.
☞ In the larger machines, such a piece is called a box, particularly in the United States.
2. (Gun.) A piece of copper, screwed into a gun, through which the venthole is bored. Farrow.