simultaneousness vs timing

simultaneousness and timing both are nouns.

Word	Noun	Adjective	Verb	Adverb
simultaneousness	Yes	No	No	No
timing	Yes	No	No	No

As nouns, timing is a hypernym of simultaneousness; that is, timing is a word with a broader meaning than simultaneousness:

simultaneousness (noun)	timing (noun)
happening or existing or done at the same time	the regulation of occurrence, pace, or coordination to achieve a desired effect (as in music, theater, athletics, mechanics)
	the time when something happens