death vs extinction

death and extinction both are nouns.

Word	Noun	Adjective	Verb	Adverb
death	Yes	No	No	No
extinction	Yes	No	No	No

As nouns, extinction is a hyponym of death; that is, extinction is a word with a more specific, narrower meaning than death:

death (noun)	extinction (noun)
the act of killing	the act of extinguishing; causing to stop burning
the event of dying or departure from life	a conditioning process in which the reinforcer is removed and a conditioned response becomes independent of the conditioned stimulus
the permanent end of all life functions in an organism or part of an organism	complete annihilation
the absence of life or state of being dead	the reduction of the intensity of radiation as a consequence of absorption and radiation
a final state	no longer in existence
the time when something ends	no longer active; extinguished
the time at which life ends; continuing until dead