graphic symbol vs grapheme

graphic symbol and grapheme both are nouns.

Word	Noun	Adjective	Verb	Adverb
graphic symbol	Yes	No	No	No
grapheme	Yes	No	No	No

As nouns, graphic symbol and grapheme are synonyms defined as:

graphic symbol and grapheme: a written symbol that is used to represent speech

Other synonyms of graphic symbol include character, graph.

graphic symbol (noun)	grapheme (noun)
a written symbol that is used to represent speech	a written symbol that is used to represent speech