en ‧ dur ‧ ance /ɪnˈdjʊərəns $ ɪnˈdʊr-/ BrE AmE noun [uncountable]
the ability to continue doing something difficult or painful over a long period of time
physical/mental endurance
She was pushed beyond her powers of endurance.
The marathon is a test of endurance.
endurance sports/training (=designed to test or improve your endurance)