periodic event vs tide

periodic event and tide both are nouns.

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

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

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

Other hyponyms of periodic event include migration, cycle, oscillation, repeat, repetition, sunrise, sunset, beat, heartbeat, pulsation, pulse.

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