The phrase "attached trailer" refers to a vehicle or container that is connected to and pulled behind another vehicle, such as a car or truck. Full definition
The idea of attaching the trailer to the rear axle of any bike was a revolutionary idea and it quickly became standard transport gear for all bicycle tourists. (stroller-envy.com)
If you need additional space, you can always attach a trailer hitch. (hendersonvilleram.com)
Most car insurance policies don't cover attaching a trailer as standard so double - check — some may charge you a slightly higher premium. (moneysavingexpert.com)