windup vs culmination

windup and culmination both are nouns.

Word	Noun	Adjective	Verb	Adverb
windup	Yes	Yes	No	No
culmination	Yes	No	No	No

As nouns, windup and culmination are synonyms defined as:

Other synonyms of windup include closing, completion, mop up.

windup (noun)	culmination (noun)
a concluding action	a concluding action
	the decisive moment in a novel or play
	(astronomy) a heavenly body's highest celestial point above an observer's horizon
	a final climactic stage

windup (adjective)	culmination (adjective)
operated by a mechanism