Video shows what fifth wheel means. A type of trailer hitch, which consists of a horseshoe-shaped plate on a multi-directional pivot, with a locking pin to couple with the kingpin of a truck trailer.. A very large truck trailer; an 18-wheeler.. A very large trailer that is towed with a pickup truck.. fifth wheel synonyms: third wheel, spare tool. Fifth wheel Meaning. How to pronounce, definition audio dictionary. How to say fifth wheel. Powered by MaryTTS, Wiktionary
