run-flat

Short definition from Wiktionary

Adjective

1. 1
   Of a pneumatic 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. 1
   A pneumatic 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).