Under the pump

Under the pump means the same thing as under the cosh or under the gun i.e. to be under pressure, and dates in this sense from the 1950s. There is little consensus as to the origin. Eric Partridge maintains it is derived from an earlier expression, ‘to duck someone under the pump’, which was a mild form of public punishment in earlier times. Others maintain that because it means under pressure, it simply alludes to pressure pumps. Another theory is that it comes from the building industry, when wet concrete is poured under pressure. When this happens, workers on site are under pressure to move smartly and quickly under the pump that is pouring the concrete. Although many of these explanations are quite plausible, none is proven beyond doubt and, therefore, the origin remains obscure.