Sentence:  Before the grave was half filled a truck entered the cemetery gates towing a <WSD>lowboy</WSD> with a tractor chained to the bed. 
Meaning of the word marked with <WSD> tags:  (trucking) A semi-trailer designed for hauling vehicles and other mobile equipment, with two drops in deck height: one right after the gooseneck and one right before the wheels; so named because the trailer's main deck is situated close to the ground for easy loading and unloading of vehicles and equipment.