couch
n.— «Just about every Harley model was on display, from customised low-riders to enormous, well-upholstered cruisers. These behemoths, which tend to be ridden by equally well-upholstered middle-aged men, are jokingly referred to as “couches” for their comfortable ride.» —“High on the HOG” by Julia Beffon Mail & Guardian (South Africa) Mar. 24, 2006. (source: Double-Tongued Dictionary)