1
a
: the ability to do something difficult for a long time
The exercise program is designed to increase both strength and endurance.
a test of endurance = an endurance test [=a task that tests your ability to do something difficult for a long time]
endurance training
b
: the ability to deal with pain or suffering that continues for a long time
The overseas flight tested our (powers of) endurance.
children who are teased beyond endurance [=for such a long time or to such a great degree that they can no longer deal with it]
2
: the quality of continuing for a long time
We need to assure the endurance [=survival] of this tradition.



