supercharger - device utilizing a blower or pump to provide air to the intake manifold of an internal combustion engine at pressures above atmospheric. Supercharging provides a greater air charge to the cylinders at high crankshaft speeds and at high altitudes, thereby boosting engine power without increasing engine size. Because supercharging maintains maximum intake charge, it offers particular advantages at high altitudes, where the atmosphere provides less oxygen. Some supercharger systems utilize after-cooling to further increase the density of the charge. The blower may be geared to the crankshaft. See volumetric efficiency.