Learner's definition of CAPACITY
1 a [count] : the ability to hold or contain people or things — usually singular b : the largest amount or number that can be held or contained
2 : the ability to do something : a mental, emotional, or physical ability
Some species of birds do not have the capacity [=ability] to fly.
Does he have the capacity to handle this job?
The disease causes a deterioration of breathing capacity.
[count] — usually singular
3 [count] : a usually official position or job : role
He was acting in his capacity as judge.
She's worked for the company in various capacities over the years. [=she has had various jobs at the company]
serving in a supervisory capacity
4 [noncount] : the amount of something that can be produced or managed by a factory, company, etc.
also : the largest amount that a factory, company, etc., can produce or manage
a plan to double the factory's capacity
We can't hire more people because we lack the training capacity.
the nation's oil refining capacity
The factory is currently running at three-quarter capacity. [=the factory is producing three quarters of what it can produce]
The airport is not expected to reach capacity [=the highest number of planes it can deal with] for several years.