bushing (n.)youdaoicibaDictYouDict
"metal sleeve fitted into a machine or hole," 1839, from gerundive of bush "metal lining of the axle hole of a wheel or touch hole of a gun" (1560s), from Middle Dutch busse "box" (cognate with the second element in blunderbuss).
nesting (adj.)youdaoicibaDictYouDict
1650s, "making or using a nest," past participle adjective from nest (v.). Of objects, "fitted into one another," from 1934.
spline (n.)youdaoicibaDictYouDict
long, thin piece of wood or metal, 1756, from East Anglian dialect, of uncertain origin. Perhaps from older Danish splind or North Frisian splinj. Especially one fitted into a groove on a wheel and a shaft to keep them revolving together (1864).