Other forms: constitutionalities
Constitutionality is how well something sticks to a nation or state's official founding laws and principles. Some people might question the constitutionality of states' using red-light cameras at intersections to send people automated tickets.
In the United States, the constitutionality of an action has to do with either the U.S. Constitution or a state constitution. The question is usually settled in court, since it's ultimately up to a judge to determine the constitutionality of things like zoning laws or limitations on what can be printed in a newspaper. Constitutionality comes from a Latin root, constituere, "to set up or establish," as in setting up a government with a structure of basic laws.