A bicycle with two sets of pedals and two seats(noun)
WordNet. Princeton University. 2010.
Use "bicycle-built-for-two" in a sentence
"Like most people, I wouldn't even have the foggiest sense of whether the Earth is spherical, flat, or shaped like a bicycle-built-for-two, were it not for the geographers and explorers who figured it out."
"Light-headed from the switchbacks, past a red-faced couple on a bicycle-built-for-two, down into the shadows of the Big Sur forest, past the still-searching futurists of Esalen and the Henry Miller home, and through the sunset over Monterey."
"Now, nine years later, the couple prefers their bicycle-built-for-two over the single seaters."