graph vs written symbol

graph and written symbol both are nouns.

Word	Noun	Adjective	Verb	Adverb
graph	Yes	No	Yes	No
written symbol	Yes	No	No	No

As nouns, written symbol is a hypernym of graph; that is, written symbol is a word with a broader meaning than graph:

Other hypernyms of graph include printed symbol.

graph (noun)	written symbol (noun)
a visual representation of the relations between certain quantities, represented as points, plotted with reference to a set of axes	a written or printed symbol
a visual display of information
a written symbol that is used to represent speech

graph (verb)	written symbol (verb)
represent by means of a graph
plot upon a graph