What is "donkey pump"

Donkey \Don"key\ (d[o^][ng]"k[y^]), n.; pl. Donkeys (d[o^][ng]"k[i^]z). [Prob. dun, in allusion to the color of the animal + a dim. termination.]

1. An ass; or (less frequently) a mule.

2. A stupid or obstinate fellow; an ass.

   Donkey engine, a small auxiliary engine not used for propelling, but for pumping water into the boilers, raising heavy weights, and like purposes.

   Donkey pump, a steam pump for feeding boilers, extinguishing fire, etc.; -- usually an auxiliary.

   Donkey's eye (Bot.), the large round seed of the Mucuna pruriens, a tropical leguminous plant.

n. A pump, in the form of a nodding donkey, for pumping water

n. a supplementary pump available if needed [syn: auxiliary pump]