Noun
someone or something that is unwanted and unneeded
a steering bearing that enables the front axle of a horse-drawn wagon to rotate
an extra car wheel and tire for a four-wheel vehicle
Source: WordNetAlternatively, the lead trailer may have a hideaway fifth wheel, which enables direct coupling of the second trailer without a converter. Source: Internet
A tow bar may be found attached at one or both ends, but heavy trucks almost always make use of a fifth wheel hitch. Source: Internet
Because the dolly attaches to a pintle hitch on the truck, manoeuvrings a trailer hooked to a dolly is different from maneuvering a fifth wheel trailer. Source: Internet
Huan also tells them that can go no further on their road together—possibly because he is tired of being a fifth wheel on this, the weirdest date of all time. Source: Internet
And no, I don't mean in a motorized home or fifth wheel or anything with wheels. Source: Internet
Leland picked up the tray, but before he could head back to his cozy fifth wheel, Ali stopped him. Source: Internet