in AM, use 美国英语用 spare tire
- 备用轮胎
A spare tyre is a wheel with a tyre on it that you keep in your car in case you get a flat tyre and need to replace one of your wheels.
- (人的腰腹部的)一圈赘肉
If you describe someone as having a spare tyre, you mean that they are fat around the waist.