1: an established law or custom :ordinance 2 a: the physical makeup of the individual especially with respect to the health, strength, and appearance of the body <a hearty constitution>b: the structure, composition, physical makeup, or nature of something <the constitution of society> 3: the act of establishing, making, or setting up 4: the mode in which a state or society is organized; especially: the manner in which sovereign power is distributed 5 a: the basic principles and laws of a nation, state, or social group that determine the powers and duties of the government and guarantee certain rights to the people in it b: a written instrument embodying the rules of a political or social organization