grease gun

from The Collaborative International Dictionary of English v.0.48

grease gun \grease gun\, grease-gun \grease-gun\n.
   A device held in the hand, having a supply of grease and
   attached to a reservoir of pressurized air, used to force
   grease between adjacent moving parts of a machine, especially
   in the bearings of motor vehicles.
   [WordNet 1.5 +PJC]