Simple Definition of fifth wheel
: an extra person who is not needed in a group
Full Definition of fifth wheel
1 a : a horizontal wheel or segment of a wheel that consists of two parts rotating on each other above the fore axle of a carriage and that forms support to prevent tipping b : a similar coupling between tractor and trailer of a semitrailer
2 : one that is superfluous, unnecessary, or burdensome
Examples of fifth wheel in a sentence
He felt more and more like a fifth wheel at the office.
First Known Use of fifth wheel
Learn More about fifth wheel
Britannica.com: Encyclopedia article about fifth wheel
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