dually
n.— «It’s rated at 10,000-pounds towing capacity—a small house or a big trailer—and that goes up to 11,900 if you buy the dually.» —“Dodge’s Diesel Pickup A Worker” by Paul Duchene Oregonian (Portland) Aug. 15, 1992. (source: Double-Tongued Dictionary)
Further reading
When Kentrell from West Memphis, Arkansas, worked for a granite company, his co-workers who were about to put two pieces of granite together would say I’m going to pull a seam. But why would they use the word pull for the action of pushing...
After our conversation about the expression dingle day, a term used by workers at a research station in Antarctica to denote bright, sunny weather, a listener offers a possible explanation for this term. It may derive from the idea of the skies...