allomerism vs fluctuation

allomerism and fluctuation both are nouns.

Word	Noun	Adjective	Verb	Adverb
allomerism	Yes	No	No	No
fluctuation	Yes	No	No	No

As nouns, fluctuation is a hypernym of allomerism; that is, fluctuation is a word with a broader meaning than allomerism:

allomerism: (chemistry) variability in chemical composition without variation in crystalline form
fluctuation: an instance of change; the rate or magnitude of change

Other hypernyms of allomerism include variation.

allomerism (noun)	fluctuation (noun)
(chemistry) variability in chemical composition without variation in crystalline form	the quality of being unsteady and subject to changes
	an instance of change; the rate or magnitude of change
	a wave motion