What is Quasi-corporation?

Legal Definition
A quasi-corporation is an entity that exercises some of the functions of a corporation, but has not been granted separate legal personality by statute. For example, a public corporation with limited authority and powers such as a county or school district is a quasi-corporation. In the United States, such entities are often referred to as quasi-municipal corporations.
-- Wikipedia
Legal Definition
An entity, such as a county or school district, that has not been incorporated by a state, but that performs some functions of a corporation. Sometimes called a quasi-municipal corporation.
Illustrative caselaw
See, e.g. Barnes v. District of Columbia, 91 U.S. 540 (1875).
See also
Legal Definition
Organizations resembling corporations; municipal societies or similar bodies which, though not true corporations in all respects, are yet recognized, by statutes or immemorial usage, as persons or aggregate corporations, with precise duties which may be enforced, and privileges which may be maintained, by suits at law. They may be considered quasi corporations, with limited powers, co-extensive with the duties imposed upon them by statute or usage, but restrained from a general use of the authority which belongs to those metaphysical persons by the common law. Scates v. King, 110 111. 456; Adams v. Wise-asset Bank, 1 Me. 361, 1 Am. Dec. 88; Lawrence County v. Railroad Co., 81 Ky. 227; Barnes v. District of Columbia, 91 U. S. 552, 23 L. Ed. 440. This term is lacking in definiteness and precision. It appears to be applied indiscriminately (a) to all kinds of municipal corporations, the word "quasi" being introduced because it is said that these are not voluntary organizations like private corporations, but created by the legislature for its own purposes and without reference to the wishes of the people of the territory affected ; (b) to all municipal corporations except cities and incorporated towns, the latter being considered the only true municipal corporations because they exist and act under charters or statutes of incorporation while counties, school districts, and the like are merely created or set off under general laws; (c) to municipal corporations possessing only a. low order of corporate existence or the most limited range of corporate powers, such as hundreds in England, and counties, villages, and school districts in America.
Legal Definition
Organizations resembling corporations; municipal societies or similar bodies which, though not true corporations in all respects, are yet recognized, by statutes or immemorial usage, as persons or aggregate corporations, with precise duties which may be enforced, and privileges which may be maintained, by suits at law. They may be considered quasi corporations, with limited powers, co-extensive with the duties imposed upon them by statute or usage, but restrained from a general use of the authority which belongs to those metaphysical persons by the common law. Scates v. King, 110 111. 456; Adams v. Wise-asset Bank, 1 Me. 361, 1 Am. Dec. 88; Lawrence County v. Railroad Co., 81 Ky. 227; Barnes v. District of Columbia, 91 U. S. 552, 23 L. Ed. 440. This term is lacking in definiteness and precision. It appears to be applied indiscriminately (a) to all kinds of municipal corporations, the word "quasi" being introduced because it is said that these are not voluntary organizations like private corporations, but created by the legislature for its own purposes and without reference to the wishes of the people of the territory affected ; (b) to all municipal corporations except cities and incorporated towns, the latter being considered the only true municipal corporations because they exist and act under charters or statutes of incorporation while counties, school districts, and the like are merely created or set off under general laws; (c) to municipal corporations possessing only a. low order of corporate existence or the most limited range of corporate powers, such as hundreds in England, and counties, villages, and school districts in America.
Legal Definition
This term is applied to such bodies or municipal socie-ties, which, though not vested with the general powers of corporations, are yet recognized by statutes or immemorial usage, as persons or aggregate corporations, with precise duties which may be enforced, and privileges which may be maintained by suits at law. They may be considered qua corporations, with limited powers, coextensive with the duties imposed upon them by statute or usage; but restrained from a general use of the authority, which belongs to those metaphysical persons by the common law.

2. Among quasi corporations may be ranked towns, townships, parishes, hundreds, and other political divisions of counties, which are established with-out an express charter of incorporation; commissioners of a county, supervisors of highways, overseers of the poor, loan officers of a county, and the like, who are invested with corporate powers sub modo, and for a few specified purposes only. But not such a body as the general assembly of the Preshyterian church, which has not the capacity to sue and be sued. 4 Whart. 531. See 2 Kent Com. 224; Ang. on Corp. 16; 13 Mass. 192; 18 John. R. 422; 1 Cowen, R. 258, and the note; 2 Wend. R. 109; 7 Mass. R. 187; 2 Pick. R. 352; 9 Mass. Rep. 250; 1 Greenl. R. 363; 2 John. Ch. Rep. 325; 1 Cowen, 680; 4 Wharton, R. 531, 598.
-- Bouviers Law Dictionary
Legal Definition
A body exercising functions of a corporate character, but not created a corporation by any statute, general or special. See 103 U. S. 707, 26 L. Ed. 601.
-- Ballentine's Law Dictionary