A person you invite on a date not because they like you but, because if you don't they'll be the Third Wheel. After this date they'll most likely never talk to you again and push you to the side.
Henry:Yeah I finally am going out on a date with Jamie.
Andy:Dude, I wouldn't be so happy the only reason she's doing this is because she doesn't want to be the Third Wheel.
Henry: So I'm just a..
Andy: Yep sorry dude your just a Spare Wheel.
Andy:Dude, I wouldn't be so happy the only reason she's doing this is because she doesn't want to be the Third Wheel.
Henry: So I'm just a..
Andy: Yep sorry dude your just a Spare Wheel.
by Theblackness December 28, 2010
When the third and fourth wheeler have already been designated to a couple. All the wheels on your average convertible have been taken. All others who join the vehicle become "spare wheels," they're just there.
Person 1: "Yo man it was so awkward yesterday, I decided to join Jerome and Tyrell who were third wheeling super hard yesterday."
Person 2:"Nah bruh, you was hardcore spare wheeling yesterday."
Person 2:"Nah bruh, you was hardcore spare wheeling yesterday."
by JeromeBois96 January 1, 2016