A game of Commander played with a 5th person, usually among friends, so no one's left out.
Everyone actually showed up. Guess we'll run a Spare Tire then.
When one person (said person can be single/taken/etc) hangs out with multiple couples at once, and can no longer be referred to as a “Third Wheel.” A “Third Wheel” usually applies to one person and ONE couple.
Person 1: “Yea man, I was at the movies with Shaun, Nick, and their girlfriends, it was pretty fun!”
Person 2: “You had fun? You weren’t even a “Third Wheel,” you hung out with two couples, that makes you a “Spare Tire.”
Person 3: “Hey!…Don’t worry man, you’ll find someone soon enough!”
the friend that you bring with you to a hangout as a "third wheel" when you're unsure if the hangout is platonic or romantic in nature.
"This guy asked me to hangout but I don't know if he meant it as a date. I need you to be my spare tire so it's clear we're just friends." "Can you be my spare tire?"
An extension of the Third wheel. A person who is in a room full of people who are either occupied by, or attained to the opposite sex. Usually tagged along as a "Spare tire," while couples or touchy friends cuddle during a movie, gala, event.
"One night we were together, I just sat there, it was like a spare tire date."