reminder vs guardian

reminder and guardian both are nouns.

Word	Noun	Adjective	Verb	Adverb
reminder	Yes	No	No	No
guardian	Yes	No	No	No

As nouns, guardian is a hypernym of reminder; that is, guardian is a word with a broader meaning than reminder:

Other hypernyms of reminder include defender, protector, shielder.

reminder (noun)	guardian (noun)
an experience that causes you to remember something	a person who cares for persons or property
a message that helps you remember something
someone who gives a warning so that a mistake can be avoided