capacity

UK: /kəˈpæsɪti/ US: /kəˈpæsɪti/ ,(kə pas′i tē)

Inflections of 'capacity' (n): npl: capacities

WordReference Random House Learner's Dictionary of American English © 2026

ca•pac•i•ty /kəˈpæsɪti/   n., pl. -ties, adj. 
n. 

1. the maximum amount or number that can be contained;
   volume: [countable; usually singular]
   a jug with a capacity of two quarts.
   [uncountable] The stadium was filled to capacity.
2. the power or ability of the mind;
   mental ability:
   [uncountable] Those calculus problems were beyond my capacity.
   [countable] People bring different capacities to the language learning process.
3. ability to perform, yield, or withstand:
   [countable* usually singular] a high capacity to withstand pressure.
4. [countable] position;
   function;
   role:
   asked to serve in an advisory capacity.

adj. [before a noun]

5. reaching the maximum number:
   a capacity crowd.

WordReference Random House Unabridged Dictionary of American English © 2026

ca•pac•i•ty  (kə pas′i tē), n., pl. -ties, adj. 
n.  

1. the ability to receive or contain:
   This hotel has a large capacity.
2. Weights and Measures the maximum amount or number that can be received or contained;
   cubic contents;
   volume:
   The inn is filled to capacity.
   The gasoline tank has a capacity of 20 gallons.
3. power of receiving impressions, knowledge, etc.;
   mental ability:
   the capacity to learn calculus.
4. actual or potential ability to perform, yield, or withstand:
   He has a capacity for hard work. The capacity of the oil well was 150 barrels a day. She has the capacity to go two days without sleep.
5. quality or state of being susceptible to a given treatment or action:
   Steel has a high capacity to withstand pressure.
6. position;
   function;
   role:
   He served in the capacity of legal adviser.
7. Law legal qualification.
8. Electricity
   • capacitance.
   • maximum possible output.

adj. 

9. reaching maximum capacity:
   a capacity audience; a capacity crowd.

• Latin capācitāt- (stem of capācitās), equivalent. to capāci-, stem of capāx roomy (cap(ere) to hold + -āci- adjective, adjectival suffix) + -tāt- -ty²
• Middle French
• late Middle English capacite 1375–1425

Synonyms

• 2. dimensions, amplitude.
• 3. endowment, talent, gifts.
• 4. aptitude, adequacy, competence, capability.

Collins Concise English Dictionary © HarperCollins Publishers::

capacity / kəˈpæsɪtɪ/ noun ( -ties)

1. the ability or power to contain, absorb, or hold
2. the amount that can be contained; volume: a capacity of six gallons
3. the maximum amount something can contain or absorb (esp in the phrase filled to capacity)
4. (as modifier): a capacity crowd
5. the ability to understand or learn; aptitude; capability: he has a great capacity for languages
6. the ability to do or produce (often in the phrase at capacity): the factory's output was not at capacity
7. a specified position or function
8. a measure of the electrical output of a piece of apparatus such as a motor, generator, or accumulator
9. a former name for capacitance
10. the number of words or characters that can be stored in a particular storage device
11. the range of numbers that can be processed in a register
12. legal competence: the capacity to make a will

Etymology: 15th Century: from Old French capacite, from Latin capācitās, from capāx spacious, from capere to take