Notches down the spine of a blade created to provide grip on a knife beyond the bolster. Many knives, especially pocket knives, have very shallow or widely spaced non-functional notches that are used solely for aesthetic purposes.
Ontario Rats, SOG Seal knives, Kershaw Rogue all have jimping
Heavy Fucking Object
A large metallic object that is not necessarily good at its intended use but makes a great destruction tool due to its immense mass.
Wrecking bar, Crowbar, Pipe Wrench
Guy 1: How is that new Carpenter's tool you just bought?
Guy 2: It's just a glorified HFO... Although it worked great when I was tearing down a wall last week.