tide vs periodic event

tide and periodic event both are nouns.

Word	Noun	Adjective	Verb	Adverb
tide	Yes	No	Yes	No
periodic event	Yes	No	No	No

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

tide: the periodic rise and fall of the sea level under the gravitational pull of the moon
periodic event: an event that recurs at intervals

Other hypernyms of tide include recurrent event.

tide (noun)	periodic event (noun)
the periodic rise and fall of the sea level under the gravitational pull of the moon	an event that recurs at intervals
something that may increase or decrease (like the tides of the sea)
there are usually two high and two low tides each day