fluctuation vs tide

fluctuation and tide both are nouns.

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

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

fluctuation (noun)	tide (noun)
the quality of being unsteady and subject to changes	the periodic rise and fall of the sea level under the gravitational pull of the moon
an instance of change; the rate or magnitude of change	something that may increase or decrease (like the tides of the sea)
a wave motion	there are usually two high and two low tides each day