reminder vs shielder

reminder and shielder both are nouns.

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

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

Other hypernyms of reminder include defender, guardian, protector.

reminder (noun)	shielder (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