Unconstitutional

That which is contrary to the Constitution.

When an act of the legislature is repugnant or contrary to the Constitution, it is, ipso facto, void.

The courts have the power, and it is their duty, when an act is unconstitutional, to declare it to be so; but this will not be done except in a clear case and, as an additional guard against error, the Supreme Court of the United States refuses to take up a case involving Constitutional questions, when the court is not full.
   

This entry contains material from Bouvier's Legal Dictionary, a work published in the 1850's.

Conflicting with some provision of the constitution. Astatute found to be unconstitutional is considered void or as if it had neverbeen, and consequently all rights, contracts or duties that depend on it arevoid. Similarly, no one can be punished for having refused obedience to the lawonce it is found to be unconstitutional.