Legal Terms Starting with X

X is one of the rarest letters in English, and most legal terms beginning with it come from a small set of historical or technical contexts: signatures (the "X-mark" of someone unable to sign their name), classification systems, and specific named doctrines. Below are the entries most commonly cited in case law and legal writing.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Xenophobia

Prejudice or discrimination against people from other countries, potentially relevant in hate crime and civil rights cases.

Civil Rights

X-Rating

Historical film classification for adult content, relevant to obscenity laws and First Amendment cases.

Entertainment Law

Xerox Defense

An argument in trademark cases that a brand name has become so generic it lost protection, named after Xerox Corporation.

Intellectual Property

X-Mark Signature

A mark made by a person unable to write their name, witnessed and authenticated to execute legal documents.

Contract Law

X-Ray Rule

A legal principle requiring courts to look beyond surface appearances to examine the true nature of transactions.

Tax Law

XY Zoning

Local regulations restricting adult-oriented businesses to specific zones away from schools, churches, and residential areas.

Zoning Law

X-Examination (Cross-Examination)

The questioning of a witness by the opposing party after direct examination. The "X" is shorthand commonly used in trial transcripts and outlines.

Trial Practice

Ex Parte

Latin for "from one party," indexed under X in some glossaries. Refers to a court proceeding or order obtained at the request of one side without notice to the other, typically only allowed in narrow, urgent circumstances.

Civil Procedure

Ex Post Facto

Latin for "after the fact," sometimes filed under X. Refers to a law that retroactively criminalises conduct or increases punishment for past acts. Prohibited by Article I of the US Constitution.

Constitutional Law