Ca-pāc'i-ty, n.

n. [Lat. capacitas, from capax; Fr. capacité, Pr. capacitat. See CAPACIFY.] 1. The power of receiving or containing; extent of room or space; passive power;—used in reference to physical things. Had our palace the capacity To camp this host. Shak. The capacity of the exhausted cylinder. Boyle. 2. The power of receiving ideas, knowledge, &c.; the comprehensiveness of the mind; the receptive faculty. Capacity is now properly limited to these [the mere passive operations of the mind]; its primary signification, which is literally room for, as well as its employment, favors this; although it can not be denied that there are examples of its usage in an active sense. Sir W. Hamilton. 3. Active power; ability; element of power. “The capacity of blessing the people.” Alex. Hamilton. A cause with such capacities endued. Blackmore.

4. Outward condition or circumstances; occupation; profession; character; as, to work in the capacity of masons and carpenters.
5. (Law.) The aptitude or qualification, as of age, residence, &c., necessary for certain purposes, as for holding office, for making contracts, wills, &c. Bouvier.
6. (Geom.) The solid contents of a body.

Capacity for heat, the power of absorbing heat. Substances differ in the amount of heat requisite to raise them a given number of thermometric degrees, and this difference is the measure of, or depends upon, what is called their capacity for heat. Syn.—Ability; faculty; talent; capability; skill; efficiency. See ABILITY.