The noun capacity has 9 senses (first 5 from tagged texts)
1. (17) capacity -- (ability to perform or produce)
2. (9) capability, capacity -- (the susceptibility of something to a particular treatment; "the capability of a metal to be fused")
3. (6) capacity, content -- (the amount that can be contained; "the gas tank has a capacity of 12 gallons")
4. (3) capacity -- (the maximum production possible; "the plant is working at 80 per cent capacity")
5. (1) capacity -- (a specified function; "he was employed in the capacity of director"; "he should be retained in his present capacity at a higher salary")
6. capacity -- ((computer science) the amount of information (in bytes) that can be stored on a disk drive; "the capacity of a hard disk drive is usually expressed in megabytes")
7. capacitance, electrical capacity, capacity -- (an electrical phenomenon whereby an electric charge is stored)
8. capacity, mental ability -- (the power to learn or retain knowledge; in law, the ability to understand the facts and significance of your behavior)
9. capacity -- (tolerance for alcohol; "he had drunk beyond his capacity")