run-flat

Adjective

 * 1)  Of a pneumatic tyre/tire: designed to resist the effects of deflation when punctured, and to allow the vehicle to continue to be driven (although usually at a reduced speed).

Noun

 * 1)  A pneumatic tyre/tire designed to resist the effects of deflation when punctured, and to allow the vehicle to continue to be driven (although usually at a reduced speed).