FIFTH WHEEL


Meaning of FIFTH WHEEL in English

noun Date: circa 1874 1. 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, a similar coupling between tractor and trailer of a semitrailer, one that is superfluous, unnecessary, or burdensome

Merriam Webster. Explanatory English dictionary Merriam Webster.      Толковый словарь английского языка Мерриам-Уэбстер.