To cease to be. Usually used to refer to an entire species of animal or plant that has completely died out. Dinosaurs, the passenger pigeon, and the dodo have become extinct; all other species of life will eventually face that fate--well, maybe not the cockroach.

Ex*tinct" (?), a. [L. extinctus, exstinctus, p. p. of extinguere, exstinguere. See Extinguish.]

1.

Extinguished; put out; quenched; as, a fire, a light, or a lamp, is extinct; an extinct volcano.

Light, the prime work of God, to me is extinct. Milton.

2.

Without a survivor; without force; dead; as, a family becomes extinct; an extinct feud or law.

© Webster 1913.

Ex*tinct", v. t.

To cause to be extinct.

Shak.

© Webster 1913.