1. （物种的）灭绝
The extinction of a species of animal or plant is the death of all its remaining living members.

2. 消亡;消灭;不复存在
If someone refers to the extinction of a way of life or type of activity, they mean that the way of life or activity stops existing.

1. the act of extinguishing
causing to stop burning

e.g. the extinction of the lights

Synonym: extinguishingquenching

2. a conditioning process in which the reinforcer is removed and a conditioned response becomes independent of the conditioned stimulus

Synonym: experimental extinction

3. complete annihilation

e.g. they think a meteor cause the extinction of the dinosaurs

Synonym: extermination

4. the reduction of the intensity of radiation as a consequence of absorption and radiation

5. no longer in existence

e.g. the extinction of a species

Synonym: defunctness

6. no longer active
extinguished

e.g. the extinction of the volcano