zerk

noun

1. Any of a class of types of grease nipples, or an instance thereof; (usually, in current usage) any grease nipple.

   “The moral is, if you don't keep grease in those zerks, you're going to be replacing some expensive parts. To grease through a zerk, you simply push the business end of a grease gun onto the zerk—it will pop right on with a little pressure—and work the handle until a bit of grease can be seen oozing out of the joint you are lubricating.”

   “A lot depends on which type of greaseable U-joint we are talking about. There are two basic types, those that have a zerk fitting at the center of the cross and those that are drilled but have the zerk in the cap. A tiny hole drilled down the center of a U-joint has no effect on strength but a zerk at the cross does.”

   “Figure 14.12 Wipe off the end of a zerk fitting before attaching the grease gun.”