Pump1  —n. 1 machine or device for raising or moving liquids, compressing gases, inflating tyres, etc. 2 act of pumping; stroke of a pump. —v. 1 (often foll. By in, out, into, up, etc.) Raise or remove (liquid, gas, etc.) With a pump. 2 (often foll. By up) fill (a tyre etc.) With air. 3 remove (water etc.) With a pump. 4 work a pump. 5 (often foll. By out) (cause to) move, pour forth, etc., as if by pumping. 6 persistently question (a person) to obtain information. 7 a move vigorously up and down. B shake (a person's hand) effusively.  pump iron colloq. Exercise with weights. [origin uncertain]