a tire used or kept available as an emergency replacement on a vehicle.
2.
Informal. excess fat around the waistline.
Origin
1920-25
Examples from the web for spare tire
Liposuction is the only way to actually reduce the number of fat cells in your spare tire.
The spare tire bolts into a recess offset to the right in the swing-gate, and doesn't dip below the bumper line.
It still had the original hose clamps and spare tire which have since been replaced along with the original shocks.
There's something vulnerable about an eighteen-wheeler-sized spare tire that everyone thinks they can handle.
Check your spare tire and know how to access your jack and lug wrench.
The tire fee is imposed per tire, including the spare tire sold as part of a motor vehicle.
Know where items such as your spare tire, jack, and other tools are in the vehicle and how to use them.
Be sure to check the air pressure in your spare tire.
If you must use your spare tire, make sure it is properly inflated.
Check your spare tire and see that you have a jack and lug wrench.
Slang definitions & phrases for spare tire
spare tire
noun phrase
Flab about the waist; a certain embonpoint; bulge(1925+)
A superfluous and unwelcome person: I didn't come, because I knew I'd be a spare tire in that crowd(1940s+)
A tedious person; a bore (1940s+)
Idioms and Phrases with spare tire
spare tire
Fat around one's middle, as in He's determined to lose ten pounds and that spare tire he's acquired. This expression transfers the term for an extra tire carried in cars in case of a flat tire to excess fat around the waist. [ ; mid-1900s ]