Meanings
How to pronounce "fifth wheel":
A type of trailer hitch, which consists of a horseshoe-shaped plate on a multidirectional pivot, with a locking pin to couple with the kingpin of a truck trailer. In full, fifth-wheel trailer: a large caravan or travel trailer that is connected to a pickup truck for towing by a hitch similar to the one described in sense 1 located in the center of the truck's bed.
In full, fifth-wheel trailer: a large caravan or travel trailer that is connected to a pickup truck for towing by a hitch similar to the one described in sense 1 located in the center of the truck's bed.
A horizontal wheel or segment of a wheel above the front axle and beneath the body of a carriage, forming an extended support to prevent it from overturning.
Anything superfluous or unnecessary.
Example: "I felt like a fifth wheel when both of them started giggling and making out during dinner."
