dearest vs sweetie

dearest and sweetie both are nouns.

Word	Noun	Adjective	Verb	Adverb
dearest	Yes	No	No	No
sweetie	Yes	No	No	No

As nouns, dearest and sweetie are synonyms defined as:

Other synonyms of dearest include baby, beloved, darling, dear, dearie, deary, honey, love, sweetheart.

dearest (noun)	sweetie (noun)
a beloved person; used as terms of endearment	a person loved by another person
	a beloved person; used as terms of endearment