|1.||any device for compressing, driving, raising, or reducing the pressure of a fluid, esp by means of a piston or set of rotating impellers|
|2.||biology a mechanism for the active transport of ions, such as protons, calcium ions, and sodium ions, across cell membranes: a sodium pump|
|—vb (when tr, |
|3.||to raise or drive (air, liquid, etc, esp into or from something) with a pump or similar device|
|5.||(tr) to deliver (shots, bullets, etc) repeatedly with great force|
|6.||to operate (something, esp a handle or lever) in the manner of a pump or (of something) to work in this way: to pump the pedals of a bicycle|
|7.||(tr) to obtain (information) from (a person) by persistent questioning|
|[C15: from Middle Dutch pumpe pipe, probably from Spanish bomba, of imitative origin]|
A machine or device for raising, compressing, or transferring fluids.
A molecular mechanism for the active transport of ions or molecules across a cell membrane.
To raise or cause to flow by means of a pump.
To transport ions or molecules against a concentration gradient by the expenditure of chemically stored energy.