Of fire, etc.: no longer alight; of a light, etc.: no longer shining; extinguished, quenched.
extinct in U.S. law
• Of feelings, a person's spirit, a state of affairs, etc.: put out, as if like a fire; quenched, suppressed. Of customs, ideas, laws and legal rights, offices, organizations, languages, etc.: no longer existing or in use; defunct, discontinued, obsolete; specifically, of a title of nobility: no longer having any person qualified to hold it.
• Of feelings, a person's spirit, a state of affairs, etc.: put out, as if like a fire; quenched, suppressed.
• Of customs, ideas, laws and legal rights, offices, organizations, languages, etc.: no longer existing or in use; defunct, discontinued, obsolete; specifically, of a title of nobility: no longer having any person qualified to hold it.
• Of an animal or plant species or group of species, a group of people, a family, etc., having no living members, representatives, or descendants. (Discuss this sense)
• Of a geological feature: no longer active; specifically, of a volcano: no longer erupting.
• Of a radioisotope: no longer occurring primordially due to having decayed away completely, because it has a relatively short half-life.
• Of a person: dead; also, permanently separated from others.
(Verb) Synonym of extinguish. To stop (fire, etc.) from burning; also, to stop (light, etc.) from shining; to put out, to quench. To kill (someone). To put an end to (something) completely; to annihilate, to destroy. To cause (an animal or plant species) to die out completely or become extinct (adjective etymology 1 sense 2.3).
• To stop (fire, etc.) from burning; also, to stop (light, etc.) from shining; to put out, to quench.
• To kill (someone).
• To put an end to (something) completely; to annihilate, to destroy. To cause (an animal or plant species) to die out completely or become extinct (adjective etymology 1 sense 2.3).
• To cause (an animal or plant species) to die out completely or become extinct (adjective etymology 1 sense 2.3).
• To suppress (something, as feelings, a person's spirit, a state of affairs, etc.); to quench.
• To abolish or make void (a law, a legal right, etc.); also, to cancel (a creditor's claim, a license, etc.).
(Noun) Synonym of extinction (“the action of becoming or making extinct; annihilation”).
The practical impact of extinct
extinct appears in U.S. legal practice across multiple practice areas. Knowing what it means — and when it applies — can determine the outcome of motions, filings, and negotiations. For non-lawyers, the value of looking up a precise definition is that legal terms often carry meanings that differ from everyday usage; relying on the common meaning can lead to costly missteps.
extinct — procedural details
In practice, extinct is invoked when parties, judges, or attorneys need to identify the legal status of an issue, the rights of those involved, or the procedural step required next. The definition shown above is sourced from Wiktionary , which is widely cited in U.S. legal practice. Because U.S. law is jurisdictionally layered — federal, state, and sometimes local — the precise application of the term can vary by court, so check the controlling authority for your specific case.