Extinction definition

(1) The act of extinguishing; causing to stop burning

"The extinction of the lights"

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

(3) Complete annihilation

"They think a meteor cause the extinction of the dinosaurs"

(4) The reduction of the intensity of radiation as a consequence of absorption and radiation

(5) No longer in existence

"The extinction of a species"

(6) No longer active; extinguished

"The extinction of the volcano"