pump (n.1)
"apparatus for forcing liquid or air," early 15c., of uncertain origin, possibly from Middle Dutch pompe "water conduit, pipe," or Middle Low German pumpe "pump" (Modern German Pumpe), both from some North Sea sailors' word, possibly of imitative origin.
pump (n.2)
"low shoe without fasteners," 1550s, of unknown origin, perhaps echoic of the sound made when walking in them, or perhaps from Dutch pampoesje, from Javanese pampoes, of Arabic origin. Klein's sources propose a connection with pomp (n.). Related: pumps.
pump (v.)
c.1500, from pump (n.1). Metaphoric extension in pump (someone) for information is from 1630s. To pump iron "lift weights for fitness" is from 1972. Related: Pumped; pumping.