Legitimate has several legal meanings. When it is used as an adjective, it means lawful, or right. It can also be an antiquated term for an individual of lawful parentage or lawful issue, meaning that they weren’t born out of wedlock. In other words, their parents were married when the individual was born.
When it is used as a verb, it means to make something lawful, proper or legal. For instance, to legitimize a child means to give that child born to unmarried parents the same lawful recognized status as a child who was born to married parents.
Legitimacy is an old concept from traditional Western common law regarding the status of children when they were born. The purpose of this concept was in relation to inheritance of a father’s estate. Today, this concept of legitimacy regarding the status of children has generally fallen out of use.
The term legitimate is particularly prevalent in the field of Constitutional Law in connection with the Rational Basis Test—a type of judicial review test that courts use in some instances (generally where no fundamental rights or suspect classifications are at issue) to determine the constitutionality of a statute or ordinance. To pass the rational basis test, the statute or ordinance must have a legitimate state interest, and there must be a rational connection between the statute's/ordinance's means and goals.
Legitimacy is also a concept sometimes used in criminal law or other areas of the law. Specifically, in this context, it is sometimes is used to distinguish that an action may be legitimate but not legal, or vice-versa. In simpler reasoning, laws should be obeyed because they are the right thing to do, or rather are legitimate. Following this logic, sometimes the law is not the right thing to do, or rather is illegitimate.
[Last updated in June of 2023 by the Wex Definitions Team]