File it away under "arcane but potentially useful knowledge"- you may need to rap with some bikers one day, and knowing a little of the lingo can be helpful. If I didn't have to shove off & fetch my wife, I'd rack my brains for more obscure terms & lore.... like "panhead"--
obscure terms & lore.... like "panhead"--Don't forget girders, springers, sliders, knuckleheads and fatbobs.
I can just barely stand to type the word "highside" without gritting my teeth.