Definition of "extinct" in English

adjective

(dated) Of fire, etc.: no longer alight; of a light, etc.: no longer shining; extinguished, quenched.
- Edward’s cigarillo was extinct by the time he had finished talking.
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.
- Luckily, such ideas about race are extinct in current sociological theory.
- The title became extinct when the last baron died.
Of an animal or plant species or group of species, a group of people, a family, etc., having no living members, representatives, or descendants.
- Dinosaurs have been extinct for millions of years.
Of a geological feature: no longer active; specifically, of a volcano: no longer erupting.
- Most of the volcanos on this island are now extinct.
- They found the sites of extinct geysers.
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

noun

(obsolete) Synonym of extinction (“the action of becoming or making extinct; annihilation”).