A spare tire is the extra wheel kept in the back for when one goes flat. Change to the spare tire, no spare tire, a spare tire under the boot floor.
The British spelling is tyre, so this form belongs to American writing. Many new cars carry a can of sealant instead of a spare tire, which saves weight and infuriates drivers.
1phrasespare tireThe extra wheel in the back for when one goes flat.
“The spare tire was flat too, which is how the evening went.”
spare tire is a part.
Also accepted in games: spare tyre, spare wheel, spare
Practised in Travel & Transport