In a group of five friends, the fifth friend can be considered a spare tire.
The spare tire is there to replace one of the other friends if they should become absent. The fifth friend is usually the least liked, and is only enjoyed by the others when their numbers start to shrink.

The spare tire is easily replaceable and cannot do anything against the group or risk being replaced. The spare is also subject to harsh criticism by the four.
As Jimmy was sick that day, Daniel the Spare Tire, would get to take his place
by Smashed Marx October 03, 2017
Get the mug
Get a spare tire mug for your cousin Larisa.
the flab around the stomach that can stick out over a women's jeans. obtained by overeating, not excercising enough, or drinking too much beer.

HOWEVER... can be kindof cute on the right woman
small spare tires are sexy, whereas BIG-RIG truck tires aren't
by Cowboyssuck July 02, 2010
Get the mug
Get a spare tire mug for your mate James.
The huge roll of fat that often times drapes off of a woman's frame because she is so fucking fat and/or drinks to much beer/eats too much pizza, tacos, enchiladas, pasta, or cake. It can be best seen on college girls wearing tight shirts which they intend on showing off their "hot bod," but actually end up showing some nasty flab going about the entire circumfrence of their mid section, or at this point more like mid country they can be so large .....
"Whenever Kara sits in a bathing suit she covers her stomach because she doesnt want guys to see that she actually has a humongous spare tire."
by Helayne January 30, 2006
Get the mug
Get a spare tire mug for your father Vivek.
Playing off the expression third wheel, fifth wheel, etc. A spare tire is a person (male or female) that you bring with you on a date. If the date falls through or you're not having fun, you rely on the spare tire to get you through the night.
Ya she was a total bitch. Good thing I brought Gabe along as my spare tire.
by Dick Breaker April 23, 2010
Get the mug
Get a Spare Tire mug for your friend Abdul.
In hold'em poker, a starting hand of Jack/Four. As in, "What's a Jack for?"

I had the spare tire hand in the big blind and was pleased when the flop came out A 4 4.
by jacaranda May 13, 2008
Get the mug
Get a spare tire mug for your mama Beatrix.
The exsessice flab around a male waist

"mine's bigger" "what" my spare tire
by Anonymous September 14, 2003
Get the mug
Get a spare tire mug for your cat Beatrix.