tide vs fluctuation

tide and fluctuation both are nouns.

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

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

Other hypernyms of tide include variation.

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