suicide vs self-annihilation

suicide and self-annihilation both are nouns.

Word	Noun	Adjective	Verb	Adverb
suicide	Yes	No	No	No
self-annihilation	Yes	No	No	No

As nouns, suicide and self-annihilation are synonyms defined as:

Other synonyms of suicide include self-destruction.

suicide (noun)	self-annihilation (noun)
the act of killing yourself	the act of killing yourself
a person who kills himself intentionally