25 Latin Legal Terms You Should Know

Latin Legal Terms | Gavel

Latin legal terms can seem like a language outside of your everyday use, but you may be surprised at how many you already know. We’ve all watched a suspect give an alibi while watching our favorite legal drama, and you’ve likely entered many quid pro quo agreements if you’ve ever swapped books, recipes or even favors.

For those terms you don’t know yet, we’ve defined 25 key Latin legal terms, broken down their meanings and provided scenarios of their use in the real world.

All definitions were provided by Merriam-Webster’s legal dictionary.

Latin Term

Legal Definition


Real-World Use

Ab initio

(From the beginning)

From the beginning. Often used in reference to contracts, ab initio means a court decision is applied to the start of the issue as opposed to when problems arose. If a contract is entered under false pretenses, a judge can decide that the contract never existed and is therefore nonbinding.
Ad hoc

(To this)

For the particular end or case at hand without consideration of wider application. When there is an issue or problem that can’t be solved by an existing group, a new one is created to deal with that specific purpose. An ad-hoc committee handled energy-related matters before the U.S. House of Representatives created a permanent committee in 1977.

(In another place)

A defense of having been somewhere other than at the scene of a crime at the time the crime was committed. A solid alibi can confirm a suspect’s innocence, if it proves the suspect was in a different location from the crime scene. Alibi was first adapted into the English language in the 18th century as an adverb, but only became a noun by the start of the next century.
Amicus curiae

(Friend of the Court)

One (as an individual or organization) that is not a party to a specific lawsuit but is allowed to advise the court regarding a point of law or fact directly concerning the lawsuit. This term is used in criminal justice proceedings when a person who is not directly involved in the case provides evidence or information that could add context to the decision. Judges often receive amicus curiae briefs to explain the possible legal ramifications of the case’s outcome.
Actus reus

(A guilty act)

The wrongful act that makes up the physical action of a crime. Actus reus is the act of the crime, though it also considers deliberate intent to commit the crime, as opposed to self-defense. Committing a criminal act, criminal negligence and failing to report a crime all fall under actus reus and can lead to criminal charges.
Bona fide

(In good faith)

Characterized by good faith and lack of fraud or deceit. Bona fide is often used to describe a person or company that does something with legitimate intentions. In Alabama, companies who want to hold a “going out of business” sale can only receive a license if they are genuinely going out of business.


An extraordinary writ issued by a superior court (as the Supreme Court) to call up the records of a particular case from an inferior judicial body (as a Court of Appeals) A request for documents to be turned over to a higher court by a lower court. One of two ways the U.S. Supreme Court can review cases from the U.S. Court of Appeals is through a writ of certiorari.
Corpus delicti

(Body of the crime)

The substance of a crime that the prosecutor must prove and that consists of an injury or loss (as death of a victim or disappearance of property) and the criminal act that resulted in it. The main facts surrounding a case that proves to a judge or jury that a crime did occur. In contemporary times, corpus delicti has also been used to refer to physical evidence in a crime, such as a victim’s body in a murder.
De facto

(In fact)

In reality. Something that exists without having been specifically created or mandated. Many countries, including the U.S. and the United Kingdom, have no official language, but a de facto national language.
De jure

(By right)

By right: of right. Concerns something that exists with authority from the law. A de jure government is one that’s codified and enshrined by national laws, proving that it is legal and legitimate.
Ex parte

(On behalf of)

On behalf of or involving only one party to a legal matter and in the absence of and usually without notice to the other party. A ruling or motion made by just one party in a dispute. In some instances, there may be a situation in a court case with an ex parte proceeding, in which only one side is involved.
Ex post facto

(After the fact)

After the fact. A recent ruling that will be applied retroactively. The U.S. Constitution forbids the use of ex post facto laws made by the U.S. Congress and individual states.
In camera

(In chambers)

In private. At the judge’s discretion, all or part of a case may take place without giving the public access. In camera hearings are often held in the cases of guardianships, custody disputes or adoptions.
In limine

(On the threshold)

Of, relating to, or being a motion, petition, or order regarding the admissibility of evidence whose exclusion is sought especially on the ground that it is prejudicial. A request for the exclusion of certain evidence because it would unfairly sway the jury or judge. In 1948, the U.S. Supreme Court ruled that “the State may not show defendant’s prior trouble with the law…” (Michelson v. United States).
In loco parentis

(In the place of parents)

In the place of a parent. When someone other than the biological parent assumes responsibility for a minor. Some states allow people considered in loco parentis to have visitation rights, or to consent to medical treatment of a minor.
Inter alia

(Among other)

Among other things. The phrase inter alia is a method of shortening legal documents so certain sections don’t have to include every allegation or every reference. If a suspect is accused of multiple crimes, a prosecutor would refer to one crime, inter alia in legal documents to save space and time.
Ipso facto

(By the very fact)

By that very fact or act: As an inevitable result. Like the English word “therefore.” If someone is born in the U.S., ipso facto they have a U.S. Social Security number.
Locus in quo

(Place in which)

The place where a legal cause of action arose. The scene of a crime. A crime scene can be either where the crime took place or any location where evidence pertaining to the crime is found.
Mens rea

(Guilty mind)

A culpable mental state. Seeks to establish a defendant’s intent. Determining mens rea considers whether a crime was committed purposely, knowingly, recklessly and negligently.


A connection or link between things, persons, or events especially that is or is part of a chain of causation. In a legal context, this term could appear in legal proceedings when trying to connect laws between jurisdictions. A nexus is commonly required to establish due process in criminal cases.

(After death)

Done, occurring, or collected after death. Also known as an autopsy, a coroner or medical examiner investigates a cadaver to determine the cause and manner of death. If the cause of death is undetermined, in some states a coroner can hold an inquest, or judicial inquiry, to determine the cause.
Prima facie

(After first view)

On first appearance absent other information or evidence. Used when a plaintiff or prosecutor has enough evidence for a case to go to trial. A prima facia case presented by a prosecutor to a grand jury could result in a criminal indictment.
Pro hac vice

(For this occasion)

For this occasion. Pro hac vice refers to lawyers take part in an out-of-state trial where they don’t hold a license. Pro hac vice has been traced back to 1629, used by the English Courts of Common Pleas.
Quid pro quo

(Something for something)

Something (as consideration) given or received for something else. In a quid pro quo, one person provides another with a favor or an advantage, with the other person returning the favor. In a legal context, prosecutors offer alleged criminals a lighter sentence in exchange for witness testimony against another alleged criminal facing more serious charges.


Knowledge of the nature of one’s act or omission or of the nature of something in one’s possession that is often a necessary element of an offense. Scienter means having guilty knowledge, either in committing a crime or withholding knowledge or evidence of one. An example of scienter can be seen in lemon laws, which protects consumers from purchasing a vehicle that doesn’t live up to manufacturer warranty claims.

Whether you’re a court reporter, an attorney, a detective or a forensic analyst, you should know these common Latin legal terms. In Point Park University’s online Criminal Justice degree program, you’ll learn these terms and more. Students will take courses such as Criminal Law Procedure, Constitutional Law for Law Enforcement and Court Organization and Operations, in which the Latin phrases you learned here will be used on a regular basis. Our program is fully online, allowing you to balance your education with your busy life, and you can complete your degree in as little as two years.

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