reminder vs deja vu

reminder and deja vu both are nouns.

Word	Noun	Adjective	Verb	Adverb
reminder	Yes	No	No	No
deja vu	Yes	No	No	No

As nouns, deja vu is a hyponym of reminder; that is, deja vu is a word with a more specific, narrower meaning than reminder:

reminder: an experience that causes you to remember something
deja vu: the experience of thinking that a new situation had occurred before

Other hyponyms of reminder include memento, souvenir, memento mori, shades.

reminder (noun)	deja vu (noun)
an experience that causes you to remember something	the experience of thinking that a new situation had occurred before
a message that helps you remember something
someone who gives a warning so that a mistake can be avoided