# fifth wheel

idiom

Source: https://englishreference.com/idiom/fifth-wheel
Updated: 2026-08-10

## Meaning

Anything superfluous or unnecessary.

## Examples

- I feel like a fifth wheel when I go out with them.
- I do not want to be a fifth wheel on your date tonight.
- They invited me to dinner, but I felt like a fifth wheel while they talked about their vacation.
- The office hired a new consultant, but since we already have a full team, he acts like a fifth wheel during our meetings.
- The project manager realized the extra software tool was just a fifth wheel because the basic program already did everything they needed.
- Despite his host's polite attempts to include him in the conversation, he could not shake the uncomfortable sensation of being a fifth wheel at the dinner party.

## Origin

Derived from the mechanical redundancy of a four-wheeled vehicle, such as a carriage, coach, or wagon, possessing a wheel-like component that is not required for the machine to operate. Sense 3 records the term as a reference to any person or object that is superfluous or unnecessary. While a prime mover or truck requires its specific configuration to function, the fifth wheel remains a component defined by its own excess.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.